I'm not exactly sure, but if the landlord kicks her out then it should be legal. The landlord obviously controls the property, and if the girl won't pay her bills then it's definitely the landlords right to kick her out. Before kicking the girl out though, I think you and the other girls should have a conversation with the other girl and find her situation. Like if there is a reason she can not pay the bills or why she is messy. It's, of course, you r right to decide to talk to her or not. But a heads up before kicking her out would definitely be the best go. I am not educated in this field, but I do know generally it is all up to the landlord. I'm aware you can not just out right kick her out. First, the landlord must phone her and ask the questions for rent. Then if she still continues to not pay, the landlord must give and an eviction notice. If she still does not follow the rules afterward, she will be kicked out. I would also make the roommate aware of the mother's situation. I doubt this was helpful, but I hope it helped at least a little bit. So, in short, you can kick her out if the landlord gives permission. (At least, that is was I could conclude to a little research.)