Step kids

Soooo I have an 8 year old from my ex husband, she talks a lot but doesn’t really give me problems other than being sassy and etc. Normal kid stuff. My current husband has 2 kids from his previous relationship... the boy is 6 and the girl is 5 but they keep being babied to the max. Like babied babied, the little girl pees her pants all the time when she sleeps over with us. Doesn’t matter what I try to do to help her, she still does it so I’m stuck washing her covers everyday until she goes back with her grandma ( my mother in law) she’s the one that babies them. Both my father in law and mother in law practically feed them in the mouth, wash them, carry them like if they were babies so when they come over they behave so bad with me, they don’t listen to me, and when I try to be a little more strict my husband gets mad because I try to tell them to stop and he says I should only worry about my own kid not his, but when they come over I’m the one that takes care of them not him. It’s getting to the point that I can’t stand them. That I wanna leave every time they are here because they’re so misbehaved. Breaking stuff from my daughters room, hiding her stuff, even gang up on her two against one and lying saying she’s the one that does things when she only likes to be on her iPod. She has her own room, as do they but they’ll go and bother her all the time. Of course I’m gonna side with my daughter because I don’t think it’s fair. I’m currently pregnant, almost time to have my baby boy but I’m scared of him being raised like that. I never babied my daughter, and I don’t wanna start with this one. I feel like they’ll try to baby him and I don’t want that. I feel so desperate because I do love the kids, but they’re attitude gets to me and no one tells them anything because they’re “little” but they’ll never learn like that smh. Anyone go through this too? Sorry for the long post, just trying to vent 😫😫😫

***kids live with grandma because they go to school where grandma lives, the mom chose to leave them there because my MIL works at the school. The mom only gets to see them like 2-3 days out of the week. My husband gets them the weekends when he’s back from work ( he leaves for weeks without coming home) when he’s here tho he has them many more days (sometimes more than the mom)

I’m trying to do just that, I’ve helped the little girl in any way possible to keep her from peeing but it still happens, I’ve talked to grandma and dad to go get her checked they won’t listen so all I do is just leave the sheets peed and don’t worry about correcting them other than defending my own kid.