DD8 speaks dreadfully to me. She answers me back, argues the toss, shouts and screams if she doesn't get her way. She's frequently mean with her older sister (9). She's also the same with DH although not to the same extent as me. It's causing a strain on our marriage. She's been like this since an early age although she can also be a very sweet girl. She's happy at school - has friends etc but is way behind esp with maths. Trying to get her to do some practise at home is a battle and as I'm often tired and exhausted, I usually give up. Any advice would be appreciated. Tia.