What do I do with my 9yr old!?!?

For real... I am 29wks & have a 9yr old daughter. We moved 600miles from family 2yrs ago. My husband has a cousin here & I was planning on having his wife watch her for me but lately she has been pretty messed up towards my daughter. She has a 3yr old son whom she lets hit, spit on, pull hair, bite & thousands over other things to my daughter. I usually just apologize to her about it but I actually told his mom the way he acts & she acted surprised. Well, thanksgiving I found out she was watching him do these things then getting on to my daughter & basically forcing her to play with him. So no more of that. Which also means no one to watch her when I am in l&d.; I thought about just offering her some incredible thing to just endure the time with them but she's super attached to me & I know she will be worried & stressed so definitely don't want that added stress on her. So what do I do with her? I don't want to torture her by making her spend all day in a delivery room then traumatize her by lettering her see her little sister turn me into a howling animal 🤣🤣 Has anyone been through this? What did you do with older siblings? HELP!