i dont see what the big deal is. i call my daughter OURS. i dont mind if my mum were to ever call her hers. the baby is part of her. i think its so amazing that your mum is already showing how much she cares for you i believe its just part of the excitment hun when you feel your part of someones experiance you can take it on as your own. not intentialy she just is very happy and excited. let it go.
It's nice that you see it in a positive light, and I wish I could, but as my mom has always been extremely controlling and overbearing, I find it a bit threatening. When she called it hers the first few times I let it slide, but she calls it hers EVERY TIME and never calls it mine. My mom has told me she won't call my child by their name if she doesn't like it, she has said she will not babysit my son if he is uncircumcised, and these are all just attempts at her trying to control me. They are empty threats, but she wants to get her way.
I know she is happy and excited. I know she is not intentionally trying to hurt my feelings or make me feel uncomfortable, but truth is, it does. I don't want to tell her to stop because I think she's being bad, I want to ask her to stop because I don't want to have bad feelings towards her.
I guess I just mean to say it's a deeper issue for me than simply "She calls it hers and it is mine wah wah wah".