My 3.5 year old daughter is causing me a lot of worry, sadness and I'm afraid, embarrassment. She's a sweet, bright and funny little girl most of the time. She's very physical and at nursery prefers running, climbing and chasing to other activities.
The trouble is that over the past month or so she has become very rough with her 'best friend' at nursery (a boy her age, and son of my friend), pulling him to the floor, pushing him, snatching toys, kicking and hitting him. It's not clear how far this behaviour is play fighting and how far it's 'mean' behaviour borne out of frustration with having to share him or other issues. Sometimes though, it definitely strays into 'mean' behaviour. Nursery have quite rightly told her she will not be able to play with him if this behaviour continues. Given that she mainly plays with him, this is no small threat.
At home, she is also sometimes lashes out at me or her little sister (8 months). It seems to be when she's frustrated or when I'm saying 'no' to something.
I think I know how to deal with it (clear boundaries and consequences, plus rewards for good behaviour) but I want to understand why this is happening. Our home life is pretty happy and not particularly stressful I don't think, though I'm spread more thin when my partner (her Dad) travels for work (up to a fortnight at a time). I find the idea that she's experiencing anxiety or stress I'm not aware of really unsetting. I also don't like this side of her and am embarrassed by it.
Has anyone experienced anything similar? What caused it do you think? how did you handle it? Did it pass?
Any help/thoughts gratefully received.