There is an aspect of DD11's personality that really has me worried. There are people in her life who are, as I call them "hot and cold." One minute they're super nice, the next they are shunning her. stbx is one of them, but there is also a girl at school who likes to play games with the other girls (manipulation, control, pit them against each other).
So two things have been happening almost simultaneously - stbx and this girl.
stbx: We've been living separately for not quite a month yet, he's had two weekends with them. The first weekend went great, the second weekend, not so much. DD became the outcast, she was sassing, talking back, etc because stbx was essentially making the kids scrub the house clean when they needed to unwind and get homework done (DD had a huge project due the following week but cleaning took priority). DD also had a lot of activities scheduled on his weekend (something stbx hates).
So I'm not sure if he was 'punishing' her because of all of her scheduled activities or if it was her attitude (which isn't new), or if it was a combination of both. stbx reacts by lavishing all of his attention on DS14 (who knows exactly what games his dad is playing). He even goes as far as to hug DS and make a point of telling him hom much he loves him...and ignores DD. She is so hurt by this, crying on the phone and wants me to come get her and take her to my house.
Fast forward to his one night last week - and he's back to his nice self with DD and she's fawning and eating it up. As if the past weekend never happened. He's best daddy again.

Meanwhile, at school this girl is trying to be better and get along with all of the other girls (she's been spoken to about her behavior). DD is sitting with one of her friends when this girl wants her to go off with her and leave the group of friends she's sitting with. DD does, and one of the friends she abandoned got upset. DD gets upset, can't figure out why this friend was so upset that she left with the girl. Then DD tells me the only reason she left her friends to go off with this girl (at the girl's request) is because she didn't want the girl to get upset and start crying. DD also tells me that this girl is being nice and she's going to play with her for as long as the niceness lasts.

It's a cycle that's been repeated ad nauseum.
I try to explain that this isn't good, that she should have a group of friends who always treat her well and with respect, but it falls on deaf ears. She continues to placate these people who are alternately mean and nice to her. It's making me crazy!
Is there anything I can do to help her? She is in therapy, but rarely opens up about what goes on at home (she finally did a little at her last session). Do I just need to wait it out and let her decide on her own that these people aren't worth being near? I'm fearful this is her pattern, and that this is what she will continue to seek in her friends and eventually her boyfriends/future husband. It would break my heart to see her follow in my footsteps.
Any advice?