
1. Demand payment for watching the kids 2. Demand the kids go with her to drop off her bf 3. Demand the kids been sent to another family member’s house if the dad won’t watch them. These are not your siblings and this not your responsibility. I’d recommend reporting that the kids are there to the building as their presence most likely breaks fire code (too many people in one apartment) and no landlord wants to deal with the fire marshal.
The fact that she’s willing to leave several children with no confirmed supervision can be considered child abandonment. I’d also still try and contact the mom and let her know what’s going on cause even if leaving the kids with your roommate is her only option she needs to know what’s going on.