I'll be watching this thread as Imogen has started pushing a bit recently. I think her problem is she's often around older children, my cousins are 5 & 7 and my neice is 3 1/2 and they can all be quite boisterous playing so she thinks thats the way you play. Its fine when shes with older ones as shes not really doing much harm, altho I still tell her not to do it but its really not nice when its younger ones.
Sorry I've not got any advice.