My sister has been staying at my home for the last week weeks with her newborn because she's mad at her husband. When my sister gets mad she gets really vindictive so she's "punishing" her husband by not letting him see their baby. I thought she would only stay for a couple days but she's been here two weeks and it feels shitty to kick out my 3 week pp sister. She's been making messes around my house and not cleaning up after herself. Just leaves dirty diapers on the floor. Not respecting our boundaries at all. She went into me and my boyfriend's room and was looking through our closet. My son ended up snapping on her and making her cry because she went in his room for some reason and changed my niece on his bed. My niece had a blow out and my sister did nothing besides cover the poop on his sheets with his quilt and just left in there. He found it. Found out she was in his room and left poop on his sheets and yelled at her and she started crying and calling him vile. She's causing a lot of drama and I feel bad because I know she's pp. I also know she's being vindictive and just trying to hurt her husband until she feels he's been punished enough. Not sure what to do.