My DD, soon to be 1, has always been very easygoing and gentle until the last ten days/two weeks. She developed a cold and was teething last weekend, and was exceedingly grumpy, which I put down to illness. She was throwing stuff on the ground, shrieking, struggling - which I didn't mind but she seems better now and the bad temper has continued. This morning I took her to a play group and she was being very possessive of me, and the toys, so much so that she even started slapping some of the other babies. I was really appalled as it does look like it's motivated by aggression. I don't know what's caused it or how to stop it but it's a worry. The other mums didn't look very pleased at all, understandably. I feel her personality has changed and wonder if it's something I've done, but my partner and I have never slapped her, and don't intend to, so I'm baffled as to where this behaviour has come from. Help!!