
426 S.E.2d 410 (1993)
109 N.C. App. 136
STATE of North Carolina
v.
Deborah Mae AINSWORTH, and Duncan Graham Ainsworth, Defendants.
No. 9223SC6.
Court of Appeals of North Carolina.
March 2, 1993.
*414 Atty. Gen. Lacy H. Thornburg by Sp. Deputy Atty. Gen. James Peeler Smith, Raleigh, for the State.
Gregory J. Brewer, Wilkesboro, for defendant-appellant, Duncan Graham Ainsworth.
Dennis R. Joyce, Wilkesboro, for defendant-appellant, Deborah Mae Ainsworth.
EAGLES, Judge.

Deborah Mae Ainsworth's Appeal

I. Motion to Dismiss
Defendant Deborah Ainsworth first argues that the trial court erred by denying her motion to dismiss the charges of first degree rape and indecent liberties. We disagree.
In considering this motion, the trial court was required to view the evidence in the light most favorable to the State, giving the State the benefit of every reasonable inference to be drawn from it. If there was substantial evidencewhether direct, circumstantial, or bothto support a finding that the offense charged was committed and that defendant committed it, the case was for the jury and the motion to dismiss was properly denied.
State v. Degree, 322 N.C. 302, 307-08, 367 S.E.2d 679, 683 (1988) (citations omitted).

A. First Degree Rape

1.
Defendant appears to argue in her brief that the first degree rape indictment was insufficient because it failed to charge her explicitly with aiding and abetting. Her brief states:
Deborah Ainsworth was tried for this offense under an indictment which charged that she "... willfully and feloniously did carnally know and abuse [her son]." The question of abuse aside, Deborah Ainsworth did not carnally know her twelve year old son.... However, Brenda Morrell did. During one episode of vaginal intercourse between [the child] and Brenda Morrell, Deborah Ainsworth was in the same bed with them, having sex with her husband.
The jury had to decide whether the defendant was "guilty of first degree rape because of aiding and abetting...."
*415 This issue, although addressed in the context of armed robbery, has already been resolved against the defendant. State v. Ferree, 54 N.C.App. 183, 184, 282 S.E.2d 587, 588 (1981) ("[A] person who aids or abets another in the commission of armed robbery is guilty under the provisions of N.C.Gen.Stat. § 14-87, and it is not necessary that the indictment charge the defendant with aiding and abetting."). Accordingly, this argument is overruled.

2.
Defendant next questions whether a mother may be found guilty of first degree rape on a theory of aiding and abetting when her twelve year old child engaged in intercourse with an adult woman in her presence and the mother did not take any reasonable steps to prevent the intercourse. Defendant maintains that this conduct does not fall within the traditional definition of one who aids or abets another commit a crime.
The State argues that State v. Walden, 306 N.C. 466, 293 S.E.2d 780 (1982) controls resolution of this issue. In Walden, evidence was presented that a mother was present when her small child was hit repeatedly with a belt over an extended period of time. During the assault, the mother looked on but did not say or do anything to stop the beating. On appeal our Supreme Court was faced with the issue of "whether a mother may be found guilty of assault on a theory of aiding and abetting solely on the basis that she was present when her child was assaulted but failed to take reasonable steps to prevent the assault." Id. at 468, 293 S.E.2d at 782. Answering the question in the affirmative, our Supreme Court held:
[W]e believe that to require a parent as a matter of law to take affirmative action to prevent harm to his or her child or be held criminally liable imposes a reasonable duty upon the parent. Further we believe this duty is and has always been inherent in the duty of parents to provide for the safety and welfare of their children, which duty has long been recognized by the common law and by statute. This is not to say that parents have the legal duty to place themselves in danger of death or great bodily harm in coming to the aid of their children. To require such, would require every parent to exhibit courage and heroism which, although commendable in the extreme, cannot realistically be expected or required of all people. But parents do have the duty to take every step reasonably possible under the circumstances of a given situation to prevent harm to their children.
In some cases, depending upon the size and vitality of the parties involved, it might be reasonable to expect a parent to physically intervene and restrain the person attempting to injure the child. In other circumstances, it will be reasonable for a parent to go for help or to merely verbally protest an attack upon the child. What is reasonable in any given case will be a question for the jury after proper instructions from the trial court.
.... It remains the law that one may not be found to be an aider or abettor, and thus guilty as a principal, solely because he is present when a crime is committed. It will still be necessary, in order to have that effect, that it be shown that the defendant said or did something showing his consent to the criminal purpose and contribution to its execution. But we hold that the failure of a parent who is present to take all steps reasonably possible to protect the parent's child from an attack by another person constitutes an act of omission by the parent showing the parent's consent and contribution to the crime being committed.
Walden at 475-76, 293 S.E.2d at 786-87 (citations omitted).
Here, the defendant failed to take any steps to prevent the attack on her child. Indeed, the State's evidence shows that the defendant lay on the same bed as the one in which her twelve year old child was being raped without uttering a single word in his defense. Moreover, at that time there did not appear to be any danger to the defendant. This conduct clearly falls within the Walden holding.
*416 Defendant argues that Walden is factually distinguishable from the instant case because, unlike Walden, "[t]here clearly is no physical harm, attack, small child or retarded child involved in this case." We disagree. While the threat of physical harm, including death, to the child in Walden was arguably more immediate than that here, it was no less severe. We would be blind to both the cold reality of today's world of sexually transmitted diseases and emotional damage resulting from sexual abuse if we were to hold that the child here was placed at any lesser risk than the child in Walden. Moreover, as was elicited during the sentencing hearing below, the child here was exposed to an event which could have severe psychological repercussions requiring long term treatment.
Furthermore, we note that our decision also comports with the more recent holding in State v. Oliver, 85 N.C.App. 1, 354 S.E.2d 527, disc. review denied, 320 N.C. 174, 358 S.E.2d 64 (1987). In Oliver, the victim, a sixteen year old girl with a full scale IQ of 66 or less, testified that her mother was in bed with her at the time that she was raped by another person, and that her mother was also touching her during that time. Our Court held that there was sufficient evidence to find that the mother had the opportunity to avert the rape but failed to do so. Our Court then concluded, based on Walden, that the mother was guilty of aiding and abetting the second degree rape of her child.
Defendant's argument is overruled.

3.
Defendant next argues that the State failed to show that the defendant had any criminal mens rea. Criminal mens rea is not an element of statutory rape. State v. Rose, 312 N.C. 441, 445, 323 S.E.2d 339, 342 (1984) ("Consent is no defense if in fact the child was not [over the prescribed age], even if defendant, by reason of the child's appearance or representations, believed in good faith that the consenting child was over the prescribed age."). Defendant argues, however, that "[b]oth state and federal constitutions require that a crime punishable by life in prison require some mens rea, U.S. Const. Amend. XIV; N.C.Const. Art. I, §§ 19, 23, 24." We have carefully considered this argument and find it to be without merit.
Finally, during oral argument defendant contended that the trial court's instruction on aiding and abetting incorrectly explained the duty of a parent to protect her child. This argument has been abandoned by defendant's failure to bring it forward in her appellate brief. N.C.R.App.P. 28(b)(5). Nevertheless, in our discretion and pursuant to N.C.R.App.P. 2, we have carefully reviewed the instruction and find it to be without error.

B. Indecent Liberties
Defendant next argues that the trial court erred by failing to dismiss the indecent liberties charge. We disagree.
In order to maintain a conviction for indecent liberties
the State must prove (1) the defendant was at least 16 years of age, (2) he was five years older than his victim, (3) he wilfully took or attempted to take an [immoral, improper] or indecent liberty with the victim, (4) the victim was under 16 years of age at the time the alleged act or attempted act occurred, and (5) the action by the defendant was for the purpose of arousing or gratifying sexual desire.
State v. Rhodes, 321 N.C. 102, 104, 361 S.E.2d 578, 580 (1987). "[I]t is not necessary that there be a touching of the child by the defendant in order to constitute an indecent liberty within the meaning of N.C.G.S. 14-202.1." State v. Truman, 52 N.C.App. 376, 377, 278 S.E.2d 574, 575 (1981). Moreover, sexual gratification may be inferred from the evidence relating to the defendant's actions. Rhodes, 321 N.C. at 105, 361 S.E.2d at 580.
Defendant argues that the State failed to present evidence that she improperly, immorally or indecently touched the child, that she induced the child to touch her, or that she induced the child to touch Brenda in order to arouse and gratify her own *417 sexual desire. The State argues that neither statute nor case law requires that the sexual gratification be that of the defendant. Because we find evidence from which a jury could find that Deborah's sexual desires were aroused or gratified, we do not reach the argument raised by the State.
Only two elements are even arguably at issue here: (1) that the defendant willfully took or attempted to take an immoral, improper or indecent liberty with a child (2) for the purpose of arousing or gratifying sexual desire. The State presented evidence which tended to show that the defendant knowingly (1) engaged in anal intercourse with Duncan in the presence of her child; (2) engaged in "vaginal intercourse" with another woman in the presence of her child; and (3) watched her child engage in vaginal intercourse with an adult woman. We hold that the jury could reasonably infer from these acts that the defendant wilfully engaged in an immoral, improper or indecent liberty with the child to arouse or gratify her own sexual desire. This argument is overruled.

II. Sentencing
Defendant next argues that the imposition of a mandatory life sentence for her first degree rape conviction constitutes cruel and unusual punishment. In State v. Davis, 101 N.C.App. 12, 398 S.E.2d 645 (1990), disc. review denied, 328 N.C. 574, 403 S.E.2d 516 (1991), this Court said:
Our Supreme Court has rejected such an argument on many occasions. State v. Spaugh, 321 N.C. 550, 556, 364 S.E.2d 368, 373 (1988) ("imposition of sentences of life imprisonment for such offenses [first degree rape and first degree sexual offense] does not violate the prohibition against cruel and unusual punishments")[.]
Id. 101 N.C.App. at 23, 398 S.E.2d at 652. Accordingly, this assignment is overruled.

Duncan Graham Ainsworth's Appeal

I. Motion to Dismiss
Defendant Duncan Ainsworth first argues that the trial court erred by denying his motion to dismiss the charges of first degree rape, sexual activity by a substitute parent and indecent liberties. We disagree.

A. First Degree Rape
Defendant argues that the trial court erred by failing to dismiss this charge because (1) there was insufficient evidence that the defendant aided or abetted Brenda and (2) the defendant did not have the requisite mens rea. We disagree.
The mere presence of the defendant at the scene of a crime, even though he is in sympathy with the criminal act and does nothing to prevent its commission, does not make him guilty of the offense. To sustain a conviction of the defendant, as [a] principal ..., the State's evidence must be sufficient to support a finding that the defendant was present, actually or constructively, with the intent to aid the perpetrator in the commission of the offense should his assistance become necessary and that such intent was communicated to the actual perpetrator. Such communication of intent to aid, if needed, does not, however, have to be shown by express words of the defendant, but may be inferred from his actions and from his relation to the actual perpetrator. "When the bystander is a friend of the perpetrator and knows that his presence will be regarded by the perpetrator as an encouragement and protection, presence alone may be regarded as encouragement."
State v. Amerson, 316 N.C. 161, 166-67, 340 S.E.2d 98, 101 (1986) (quoting State v. Rankin, 284 N.C. 219, 223, 200 S.E.2d 182, 185 (1973)) (citations omitted).
Defendant, citing what could be viewed as exculpatory evidence, argues that the evidence presented at trial does not support his first-degree rape conviction. We disagree. The State presented the following evidence at trial: (1) Brenda heard the defendant call the child down to the bedroom; (2) when the child walked into the room the defendant was lying naked on the bed with Deborah and Brenda who were also naked; (3) the defendant and his wife, Deborah, had been sharing their bed *418 with Brenda for some time; (4) the child testified that Duncan pulled his shorts and underwear half way off; (5) Brenda heard the defendant tell the child to go to her side of the bed; and (6) when the child engaged in vaginal intercourse with Brenda, Duncan and Deborah, lying in the same bed, were also engaged in a sexual act. We hold that this evidence, taken in the light most favorable to the State, is sufficient to withstand the defendant's motion to dismiss the charge of first degree rape based on aiding and abetting. See State v. Amerson, 316 N.C. 161, 340 S.E.2d 98 (1986).

B. Sexual Activity by a Substitute Parent
Defendant next argues that the trial court erred by denying his motion to dismiss the charge of sexual activity by a substitute parent under G.S. § 14-27.7. Defendant was convicted based on the theory of aiding and abetting.
Defendant did not object at trial to the trial court's jury instruction on this charge, and he does not argue that it was error. Indeed, defendant states in his brief that "the defendant does not assign as error any convoluted jury charge, the charge being perhaps the best possible effort under the circumstances...." We have examined the evidence presented by the State, and we find it sufficient to prove each element of the offense charged. Accordingly, this argument is overruled.

C. Indecent Liberties
Finally, defendant argues the trial court erred by denying his motion to dismiss the indecent liberties charge. We disagree.
We previously set out the requisite elements of the indecent liberties charge and relevant related rules in our discussion of Deborah Ainsworth's appeal, supra. We need not restate them here. It is sufficient to note that the defendant here argues the State failed to present evidence that (1) his conduct was for the purpose and in fact did arouse or gratify his sexual desires, or (2) that he acted wilfully. The State responds with the same arguments here it made in Deborah Ainsworth's appeal, supra.
At trial, the State's evidence tended to show, among other things, that the defendant (1) called the child into his bedroom to watch sexual activity between Deborah and Brenda; (2) called the child over to the bed and then pulled the child's shorts and underwear half way off; (3) knowingly engaged in anal intercourse with Deborah in front of the child; (4) instructed the child to have Brenda perform oral sex upon him; (5) watched as the child engaged in vaginal intercourse with Brenda; and (6) called the child over to him to observe while he (Duncan) was ejaculating. We hold that the jury could reasonably infer from this evidence that the defendant wilfully engaged in taking an immoral, improper or indecent liberty with the child to arouse or gratify his own sexual desire. This argument is overruled.

II. Sentencing
Defendant next argues that the sentence of life imprisonment for first degree rape violates his constitutional rights to be free from cruel and unusual punishment. This issue has been decided contrary to the position advocated by the defendant. State v. Davis, 101 N.C.App. 12, 398 S.E.2d 645 (1990) (citing State v. Spaugh, 321 N.C. 550, 556, 364 S.E.2d 368, 373 (1988)). This assignment is overruled.

III. Joinder
By his next assignment, defendant argues that the trial court committed prejudicial error by granting the State's motion to join his trial with the trial of Deborah Ainsworth.
G.S. § 15A-926(b)(2) provides in part:
Upon written motion of the prosecutor, charges against two or more defendants may be joined for trial:
a. When each of the defendants is charged with accountability for each offense; or
b. When, even if all of the defendants are not charged with accountability for each offense, the several offenses charged:
1. Were part of a common scheme or plan; or
2. Were part of the same act or transaction; or
3. Were so closely connected in time, place, and occasion that it would be *419 difficult to separate proof of one charge from proof of others.
Clearly, defendant's case falls within the parameters of G.S. § 15A-926(b)(2). "When joinder is permissible under the statute, whether to sever trials or deny joinder is a question lodged within the discretion of the trial judge whose rulings will not be disturbed on appeal unless it is demonstrated that joinder deprived defendant of a fair trial." State v. Ruffin, 90 N.C.App. 712, 714, 370 S.E.2d 279, 280 (1988). We have examined the record here in light of defendant's arguments under this assignment and conclude that he was not deprived of a fair trial. Accordingly, we hold that the trial judge did not abuse his discretion by granting the State's motion for joinder.

IV. Motion to Suppress and Motion for Change of Venue
Defendant's sixth assignment of error reads as follows:
6. The trial court erred by not making timely findings of fact and conclusions of law prior to denying defendant's Motions to Suppress and Motion for Change of Venue, in violation of N.C.G.S. 15A-977(f).
Under this assignment defendant argues that (1) the trial court did not make timely findings and conclusions; (2) that an x-rated video tape should have been suppressed; (3) that the day before trial a new superseding indictment was issued charging the defendant; and (4) that the findings and conclusions made by the trial court as to defendant's motion to suppress and motion for change of venue were insufficient.
"`[T]he scope of review on appeal is limited to those issues presented by assignment of error in the record on appeal.'" Boyd v. Nationwide, 108 N.C.App. 536, ___, 424 S.E.2d 168, 172 (1993) (quoting Koufman v. Koufman, 330 N.C. 93, 98, 408 S.E.2d 729, 731 (1991)). Here, the defendant has only assigned error to the timeliness of the trial court's findings and conclusions. Accordingly, his other arguments are overruled.
In State v. Horner, 310 N.C. 274, 311 S.E.2d 281 (1984) the trial court ruled on the defendant's motion to suppress at trial and later reduced his ruling to writing, signed the order and filed it with the clerk. In concluding that the trial court's procedure was permissible, our Supreme Court said:
Where the trial judge makes the determination after a hearing, as in this case, he must set forth in the record his findings of fact and conclusions of law.... The statute does not require that the findings be made in writing at the time of the ruling. Effective appellate review is not thwarted by the subsequent order. Defendant has not shown prejudice from the failure of the trial court to make the findings at the time that the rulings were made during the suppression hearing. The assignment of error is meritless.
Id. at 279, 311 S.E.2d at 285 (citations omitted).
Here, as in Horner, the trial judge ruled on defendant's motion to suppress at trial. After trial, the court reduced his ruling to writing, signed the order and placed it in the record.
Defendant argues, however, that Horner is distinguishable because in Horner the trial judge delayed only ten days after trial before signing his order while here the trial judge delayed nearly four months before signing his order and placing it in the record. We disagree. The determinative issue is whether defendant was prejudiced by the delay. The defendant has failed to show that he was prejudiced by the failure of the trial court to make more prompt findings and conclusions on his motion to suppress.
Similarly, we hold that the defendant has failed to show any prejudice resulting from the trial court's failure to make more timely findings and conclusions on his motion for a change of venue. Accordingly, this assignment is overruled.
No error.
COZORT and WYNN, JJ., concur.
