Well, you have to wonder what she's feeling when she is the one who has has a major change in her living situation. I would suggest some counseling for you, your husband and her mother and the 4 of you to make sure that the messages she's interpreted from this big change are what the adults intended. She could be having trouble processing her emotions as she has in effect lost her full time parents of 5 years. That can make her feel tremendously undervalued when she is the one that has to adjust to all the changes in the lives of the adults around her. I was divorced when my child was young, she is now an adult and we way,way underestimated the emotional impact of the divorce and changes we experienced in our living situations, dad re married, I went to work, dad divorced again, I remarried, dad moved, dad remarried again. Too much for a child to process and even if she says she's okay, children tell you what they think you want to hear. With the troubles my daughter has had as an adult, I would actually highly recommend to others that they stay together "for the kids" until like 12-14 years old, unless it's a totally unacceptable situation and I never thought I would hear myself say that! Of course, I realize that's not an option for you either, I'm really just sharing that divorces when children are very young are more damaging than we think. (Okay that's not a message I would have wanted to hear at your stage either but I wish someone had told me these possibilities) I would also suggest that ramping up the discipline - been there, too - is not necessarily the answer. If the acting out is rooted in her inability to sort out her emotions, so she displays inappropriate emotions, which are then rejected in her environment, ramping up discipline is really just one more way of saying "we don't accept what you're feeling" and you'll actually make it worse. Please read about validation and boundaries. Validation is a communication technique to acknowledge and support the child's feeling, empathize with that feeling and then transition to what you need them to do. Please consider this, my thoughts and prayers are with you.