Cut off toxic parent

I have a very toxic parent she os only toxic to her daughters and she drew the line when she insulted my boyfriends race (i didnt tell him hes upset with her as it is) she doesnt even know im pregnant and im almost 19 weeks i just want to stop talking with her i only have one party with her this summer and dont even want to talk to her i dont want to invite her to my baby shower i know if i drop her the whole family will go with her what do i do im so stressed out