I have a brother who acted like that as a teen. Unfortunately for him, my parents behaved as Engatwork describes his wife. They excused stuff when it was little so that when things finally got big, it was way more than they could handle. It took him nearly 10 years of hazardous living to finally get his head on straight. I don't know what advice to give. You are obviously not in denial and you love the kid. Those are two things you have going for you and for her.