So the question, aside from anything else is, is it proper to suggest trying (ADHD) medication and seeing what happens, as opposed to trying to figure out what the 'diagnoses' actually are and then trying to treat them accordingly?
What problems are you seeing, both at school and in other contexts, and what is the severity of these problems? That is, to what extent do these problems interfere with your DD's life, and, if the problems meet the severity threshold, are they also the problems that these meds are designed to treat? That, to me, is the question that determines whether meds would be appropriate or not.
Our DS (2E, autism) improved his behavior significantly with the help of both a med for anxiety and one for attention. This was not something we leapt into, but something that we gradually became desperate enough to try. The biggest win was in DS's self-esteem; with the decrease in negative behaviors he felt much more able to manage himself, and he stopped feeling so awful about his own behavior. He was also much more able to access the other kinds of therapeutic teaching we were doing with the help of the meds, so they started a virtuous cycle for him.
One has to be careful in medicating kids who are on the autism spectrum with stimulant-type ADHD meds because they can sometimes increase anxiety, and therefore can also increase the negative behaviors that are associated with anxiety. We use an expert prescriber (not our regular pediatrician) who really knows both our kid and the med options. We started DS on Strattera, which is non-stimulant; now, at age 10, he can handle the stimulant med and it is more effective in helping him manage himself.
ADHD meds don't necessarily make a child more pliable; they increase focus and decrease impulsivity. I wouldn't be that worried about a "false positive" from these meds; if they help, they help.
Hope that helps.
DeeDee
