Our sixteen year old daughter with high-functioning autism has developed an obsessive hatred of her mother. If my wife says anything to her it's usually on a polite day "go away" and a normal day something worse. She won't sit at the same table, accept anything from her and would not even open birthday presents. They used to have a great relationship, but now it's really stressful. She imparts no information about anything and will accept no guidance or instruction. Anything her mum asks or has suggested she will do the opposite regardless of consequences. Almost impossible to manage and at wit's end. Have dealt with lots of teenage angst with other siblings, but this is extreme. Any ideas?