Your wife's diet is almost all sugar! Fructose, glucose, starches which break into glucose, lactose, galactose. Where's the protein other than in the milk? Only fat source, too, IIRC.
I read your post with a great deal of hope and regret. Medicating a child with anti-psychotics and stimulants is not the answer. You are absolutely right to question this and consider other contributing factors for your daughter's condition.
Previous posts offer good advice regarding diet changes, etc., so I won't add to that.
What I will say is that I strongly urge you to reconsider giving your child these meds. I am not a doctor but am presently in the process of withdrawing from an anti-psychotic, given for insomnia if you can believe it, and it has wreaked havoc with my health and mind. The newer class of anti-psychotics, of which Risperdol is one, are not given to children. This is in their own literature. I do not know what this doctor is thinking as these drugs are dangerous and debilitating.
There is a website called Beyond Meds which can give you good information on drugs used in the mental health system.
I have a daughter who is 14 now. She was extremely challenging from the get-go. She was given an ADHD/learning disability label also. I find that if she stays away from sugar, simple carbs and most dairy, her mood is improved and she concentrates better. As she gets older, she has used behavioral techniques to manage herself and she is a lovely,bright and happy child.
Don't be discouraged and trust yourself.