Move on - as my mother would say 'pick your battles' - this is a battle you can't win - I've been in jobs where I couldn't use my full skills/experience/training, and it's brain-numbing.

Nannies, teachers, people who work with children are often not respected...regardless of how professional, skilled, intelligent and educated they may be...

It's a pity for the child (I know it's easy to form attachments) but if the parents are letting her run rings around you, then you are just being treated like an old-fashioned 'maid'...no status whatsoever...

There are plenty of families out there who truly *need* a nanny - how fast can you move on ??