Ummm how do i handle this... mother in law issue?

im 36 weeks and 3 cm and me and my husband dot want any body in the room with us while the baby is being born and while were in labor anyway my problem is his mother wants to be in there and she isnt taking no for an answer i tol her that im not comfortable with anybody in there because im not going to want to be wearing cloths and she just said you dont have nothing i dont then she just walked away now i learn that shes invited her mother and sister into the room i dont want to be rude and just say your not ganna be in there because we live with her and shes a little crazy shes bipolar and going through menapause and trying to quit smoking and frankly im scared of her. my husband has tried talking to her and she didnt listen to him either anyone else has this sort of problem how do i handle this