My 19mo almost 20 month baby girl has been acting up crazy lately. She keeps pinching & hitting & biting & pulling hair, not just to me but everyone. It seems like it's getting worse. I pop her on her butt but it doesn't phase her, I try holding her hands and saying "no", I try showing her to be "nice, soft, gentle". I have tried putting her in time out. She still doesn't get it. Does any one else's baby do this?