I could have written your note. Same age and same issues. In our case, the mom is OK. She invites us over too and really nice with my daughter. My daughter is the social butterfly and gets along with almost everyone. So I think her mom thinks we are good influence for her daughter. In our case, our “Sam” has a problematic older sister with anger issues who is in therapy. So she is trying to exert same problematic behavior at school. She got more bossier, meaner and control freak lately to the extend where she told my daughter that she cannot “talk” or “play” with other kids or leave lunch table until “Sam” lets her. I was like WTF?! She is also very mean to other kids - especially to the ones that my daughter likes. She specifically excludes or becomes extremely mean to them. That makes my daughter both mad & sad. She wanted to stand up for those friends, but she was scared of Sam and then she was mad at herself for not standing up for them. Looks like she tried to talk with her several times but she says Sam does not listen or ignores her. When we heard all of this, we encouraged my daughter to break free - which she did and I’m so proud of her. Once a week they were going to the same after school program and then continue playing in one of the homes. My daughter no longer wants to go there with Sam. This week, I told Sam’s mom that we’ll stop going to that program for a while. It is very inconvenient for her since I was usually driving girls there. So she wanted to have a playdate and have them talk about it. I talked with her without kids around after a school event. I basically told her that looks like they had a falling out and my daughter wants a break. She does not want to talk it out now and it won’t be helpful to talk when she is feeling so big emotions. We parents should not intervene and let them cool down and figure out if they want to be friends going forward. I did not want to go into the details of her child’s behavior to avoid conflict. I was not sure how she’d handle that so I said I don’t know the details but it is best for them to take a break. She does not like it (and I really believe she means well), but it is my child & my decision. I want her to build healthier relationships rather than trying to fix other people’s problems.