Childish game’s 💙

So my son is 4 months old and my mom has been giving me h3ll since I’ve been in the hospital having him. She is pretty much threatening of my sons dad mother & grandmother she doesn’t want them around my son at all. If she knows that we’re going over to his Gigi house (great grandma) or Mimi house (Dad’s mom) she has a total fit and will give me attitude for the rest of the day. I don’t know how to go about this situation, now that I had my baby & making more money at work due to switching departments I am moving back into my own apartment in August. My sons Gigi or Mimi hasn’t done anything too my mom they barely remember her name, they don’t speak about her or anything their main conversations be about life or my son but my mom thinks other wise . I don’t want to have to do separate parties as my son grows older so she’s going to have suck it up or don’t come. It also seems like my brother (almost near 40) like the drama , my sons Mimi unexpectedly came over today to introduce me to her fiancé & so he could meet him & they didn’t come in they stayed in the car for about 20 mins just talking to me and playing with him and somehow my brother went & told my mom and she came asking if they had came by then started ranting about how she didn’t want them near her house when all before she said she didn’t mind them coming over now it’s a problem. Has anyone else gone through similar situations? What should I do if one of the grandmothers doesn’t like the others for no reason?