S.P.
The fact that your a single mom, working to support you and your daughter has probably given her some issues with attention. Being that she's at school most of the day and when you get home you may be tire. I dunno, but you sound like me and my son. I am a single mom of a 3 1/2 year old boy who is pulling the exact same thing all of a sudden. It may be a phase. Just try to pay attention and see if there isn't an issue with her that she may be acting out aggression because she's feeling lonely. I have been thinking about that with my son. It's hard when your a single parent. But your not a failure. Keep up the good Work.
S. in Palm Harbor