Hello! My child recently applied to colleges and am anxiously awaiting to hear back. She has taken a heavy course load at her high school, in addition to an online AP class that is not for high school credit, and is not a required class. I am very concerned that she will not finish the online AP class, and I am wondering if colleges will request to see the transcript from it. She denoted it on applications under the section in the Common Application where it asks questions about your classes/transcript. Any feedback would be greatly appreciated 
You must disclose all courses taken for credit.
Can she withdraw from the online AP not required course?
That depends on the rules of the institution administering the course.
It also may depend on the requirements of the colleges you apply to. Spend the time to go through things on a case by case basis very carefully.
if it is not for credit, then I would not disclose it because it is just for fun.
@bopper, it sounds like she already disclosed in on her application. Just not the grade.
Not only that.
Most college applications IME require students to submit transcripts of all courses taken/attempted during HS even if it was “taken for fun”.
And if was already disclosed earlier, not sending the transcript with the final grade or withdrawing will raise some serious questions by the adcoms.
IME you only need to disclose courses taken for credit after you enroll in high school. You do not need to submit courses taken in middle school for college credit. It’s similar to ACT and SAT exams taken before high school that are not submitted.
“not sending the transcript with the final grade or withdrawing will raise some serious questions by the adcoms.”
If the institution permits her to withdraw, I don’t think that’s necessarily a terrible red flag. It’s certainly better than the F or D she will likely get for “not finishing,” as her parent puts it. Sometimes you have to make the best of a difficult situation.