[Sundae]

Clod - be pissed with the mother.
Most of the manipulation used by a ten year old will be a kneejerk reaction - only repeated when it works. She's still trying to find her way in a tough world and the only protection she has is in two very different family situations.

It wouldn't surprise me if underneath what she is trying to achieve is to get her mother to match the discipline she finds in your household, which is bound to feel safer in comparison because it offers a steady framework of rules, rewards and consequences.

Sorry that you have to go through it again and again. Just keep doing what you're doing, it's obviously a good job even if she doesn't sometimes seem to give a lot back.