Check her allergy meds. Seriously, they can have this effect. MY DS was a moody irritated mess on Zyrtec (my friend just happened to mention he was acting like her child when he was on Zyrtec and I looked at the side efftcts and it is actually a listed side effect). There is another med that is notorious for causing quite severe behavioral problems... I forget the name of it but my niece is on it. I decline to have DS try it because the behavioral stuff was just too risky. I'll text my brother and find out what the name is and post back.