crazy mil

Need some quick suggestion . My overacting mil is coming home today ( baby is 3 months and she's coming for 3rd town 🙄 , she doesn't do any help btw, my mom is here and does everything ) so my mil when I last spoke to her said she wants my baby to call her mama 😳😳😳😳( she was teen mom and though her son is 35 she's 53) she looks young and with the tons of makeup she maintains. Guess she's offended being a grand mother and wants to show that she's mom to my 3
Months ( makes me what if she's the mom ) I am having sleepless nights thinking of how to say go to hell in a polite way( my so is pup dog to her and would do anything for her and if I tell him I don't like her being called mama as I am the mama he will be pissed with me) so I decided to tell her . But I cannot think of the most polite way that won't look bad and will do my trick . Please help