Feel like my mom wants to be my sons mom

I had a baby septemeber 26th a beautiful mixed baby boy. He's half Mexican and I'm african american which means he's mixed. Durning my pregnancy mom wasn't all that supportive talking about I was privelage just because I was getting prenatal care. That she didn't have to do any of it , I mean that's true but really. She acts like she dosent have to help with anything now that he's two weeks old, and well, beautiful. She's always trynna act like she's the one who carried him for nine months speaking up "for" me when people ask how old he is. Or what's his name and other things. Even taking off his clothes when doctors ask ME too referring to him as HER baby when he's obviously MINE she's old and has her tubes tied mind you not even pretty as me. So am I overreacting or what?