I know a person who is MR and Autistic. Ask the doctor about Depakote for anger issues. Also she could be suffering from some type of anxiety so perhaps asking the doctor about Klonopin every 6 hours would help..Just a small dosage like .25mg or 0.5mg....
And I am sure you know this but an Austistic person is very particular. They like things done in order (routine) and on there time. Must be very consistent with routine for around a month no matter the behavior.
Such as: Monday - Friday
8am Adult or Child Impact Program (there almost like a school; see therapist for info)
3pm Return home with regular schedule such as snack
Also you might want to check out to see if there is an R-Tec Bus that will come pick daughter up for the Program mentioned above. If she doesn't like knew things then it may be better for you to take her and pick her up because new people might trigger a behavior.
I hope this message finds you and your daughter doing better.