SIL is a nanny and we recently employed her to help with our 4yo twins as dh and I work. Last weekend she came with us to the playpark. While there, ds accidently pushed dd over. She was not hurt however SIL ran up and started yelling at him loudly infront of everyone and even threatened to smack him. I was furious and told her so but she said I was overreacting and she has the right to shout at them since she looks after them. Dh agreed but it's not as if she was working, it was a family day out!