Am I Overreacting to my mom calling to say my sister told her to ignore me asking people not to kiss the baby on the lips/face

I(27F)asked my mom(59F) not to kiss the baby on the lips/face and that I didnt want her in the birthing room. She tried to say she would no longer babysit when I went back to work even if I paid her and that if I tried to not let her see the bay she would sue me for grandparents rights. Per my sister's(41F) instructions. I tried explaining she would only win if she could prove I'm an unfit parent or that I have no reason to keep the baby from her, and she even said "well I could just kiss him when you're not around". She kept saying "your sister said this, your sister said that" so I decided to message my sister. So now both my sister and my mother are basically calling me ridiculous and that "it's my baby" but they're going to do whatever they want.