What should I do?

So me and my bf came up with our delivery room list already and it’s him,my best friends and my sister. Today my mom showed interest in wanting to be there(like straight up asked me if she could be) I don’t wanna boot my sister but she has he own stuff going on and I’m not sure if she’s going to be able to be there. My bf says he’d prefer my sister to my mom. What do i do?