Who to have in delivery room?

I'm starting to think about who I want to allow in the room during labor and delivery, my sil just had a baby and my mil and husband were in the room with her which made me wonder who I'm comfortable with. I want natural unmedicated birth if possible. My mom doesn't understand why or want me to be in pain if I don't have to be so I'm scared she won't be on the same page with dh and me and it will cause some drama...they haven't always gotten along either so that's probably why I'm worrying. Anyway I would still like to have her there but maybe just sit down and talk to her about my worries beforehand? I'm thinking about also having mil there if she wants to come. I haven't asked what hospital policy is for visitors or anything yet but it's a birthing center so I'm assuming a little more lenient than a typical l&d unit...who are you having in the room? What would you do in my situation?