Girl in my cl . . .?

You need to make her follow your rules. If she refuses to do the ignment you give her she needs to fail the ignment. You will need to explain to her why she failed it. I would not come right out and tell her that you know she was abused, but let her know you are available if she wants to talk to you. A far as the notebook it sounds like she may have wrote something in there that she doesn't want any one to know about. Is it possible her dad is abusing her worse than her mom and that is why she doesn't want to go home?