We know just how you feel, my parents were terrible like that!!! They still have their moments but we just had to sit down and say "no, we are BOTH mum". We tried to be subtle, but sometimes you need to be as subtle as a frypan to the head.

We are both mum, mummy, mumma, whatever Jazz feels like saying. It doesn't confuse her, just as having two grandmothers doesn't confuse children.