What I little I know about the neurological characteristics of ADHD is that it diagnostically resembles several other nebulous disorders/syndromes where brain activity shows an atypical distribution. Given what little we know about brain function, the statistical correlations of symptoms to observed abnormalities don't indicate any pathologies specific enough to be conclusively corrected by either medication or behavioral therapy. There are still major arguments, both practical and theoretical, as to whether or not the abnormalities are the result of experiences, genetic predisposition, subtle environmental factors or some combination. I think the issue is that the disease is characterized by vague sociological symptoms, while doctors treat it as though it were entirely determined by some gross physiological deficit, and the two don't always match up. Of course stimulants relieve the appearance of symptoms; the symptoms are all defined in terms of things like accomplishment and ability to concentrate for long periods of time. But those aren't basic features of personal health - they arise as a combination of many internal processes and are determined in part by external circumstances.
Even if there is some definite chemical cause that can be easily and safely treated, I think it's a bad idea on principle. Brain chemistry is one of the few things that we can learn to willfully influence within our bodies. To provide a crutch in the form of drugs deprives a person of learning to overcome a significant personal difficulty. I applaud you for helping your daughter along the harder path - best luck.
Thread derailment! I second chezilla's suggestion towards x. 'Miranda' - I was actually thinking that myself.