9 months pregnant and can’t monitor step daughter

My partner has a daughter who stays with us. Me and my partner works from home so it is easy to manage her. I spoke with my partner when I was about 6-7 months that I cannot actively watch her as I used to, because this pregnancy has not been easy and sometimes I struggle to stay awake n move around due to pain.

My partner likes to go out with friends during the day and sometimes the night and it annoys me because I can hardly move around n I’m placed on bed rest as I’m a high risk pregnancy. I worry that when he leaves his daughter with me home alone something bad can happen and i won’t be able to reach her in time (she’s 7). She’s recently back here with us as she was spending the summer holiday with her mum family.

I just don’t want to be left alone with a child I know I can’t monitor it feels irresponsible, but I’m trying not to be upset about my partner leaving her on me to just go out and have fun knowing well enough I need to rest.

Am I being selfish for wanting to rest and not be up and down? Plus I have to be working two jobs, attending my university classes online not to mention hypertension and a body that’s not doing well with pregnancy, so I already feel as if I have enough on my plate.

What makes it worst is that I know if something should happen when she is left alone in my care I would be blamed and I’m trying to avoid problems with her mum bcz my partner and her doesn’t get along.