MIL invited guests to stay with us for days.

My MIL has been staying with us these past few months due to a family emergency we were having with my husband being a military veteran, we were having a difficult time, things are better now but still a little rocky (cps case still open) My MIL has invited her sister and her daughter with her kids to fly out and stay a few days, she has taken the liberty of offering my kids room to the guests. Im a little annoyed because i am working to get my kids to stay im their room all night without going to my room in the middle of the night. Im trying to get them used to sleeping in their room, its a 3 bedroom house, main one is ours, second room the kids share because my mil sleeps in the third one. She says her and her sister will sleep in that room and her niece and her kids can sleep in my kids room. This is going to disrupt what i have been working on for weeks now. But also im annoyed she invited them to come. I am already overwhelmed about her being here, I love her but i can only handle so much, now i also have 4 other people that will be staying here for 4 days. I am having anxiety. Im sure everything will work out but its just really annoying.