well i would talk to the ped. it sounds alot like just teenager stuff...and she is probably angry that she cant control herself let alone the fact that she hasnt had her period and is pretty self conscious about her weight...also she takes pills twice a day...i would be angry too as an 8th grader too, as a kid....but i would talk to a pedetrian the one who diagnosed her ...perhaps about changing her meds...i guess ADHD medication is like any other medication...you take it for a long time your body gets used to it...i would also sit down with your daughter and explain to her about what is going on with her body...and why she could be confused....explain to her about her diagnosis...especially since she might not have a great understanding especially since she was diagnosed as a baby....i hope i helped alittle bit....
good luck
love,
inny