Really not sure where to go from here... our 12 year old daughter is turning into an incredibly unpleasant person - it's so very sad to see. She regularly shouts and speaks rudely to me, is aggressive (digging her nails in to me, chinese burns). She has no respect for boundaries if I try to limit her screen time, and has now started stealing from us and her brother. When I have tried to give consequences for her behaviour, such as stopping pocket money for a week, she stole money from my purse. I then bought a petty cash tin to keep money in, and she stole the key and helped herself. She recently took some of her brothers possessions which he needed for school, and hid them and shows no remorse whatsoever. I'm really struggling to know how to handle this.