Perhaps violent is the wrong word as she doesn't actually hit him. But she jumps on his back, pushes him over, grinds his face into the floor and is generally far too rough. I know she's only playing. If I ask her to stop or pull or off she thinks it's one big game and laughs. I have tried to lock her out of the room for 2 mins (time out) but that doesn't seem to be working either. Obviously, this is one behaviour that I can't ignore - does anyone have any tips?