My step mum often refers to herself as a grandma or nanny to my 2 year old DD. She often says it jokingly and if we are out together she will sometimes refer to me as her daughter. She now does the same with DD and will say 'my granddaughter' to people we don't know.
Family members asked on several occasions in front of her what DD will call her and I've always just said her name.
We are not close. She thinks we're closer than we are but she's said some horrible things to me that I will never forgive her for. She's not been a 'mum' to me IMO in any other sense other than being married to my dad. So for this reason it really bugs me. But obviously none of this affects DD. So Aibu? Should I ask her to stop?