Stella_luna, I can totally relate. Our DD is 8 and got totally dumped by her good friend when the friend got new neighbors. It was soooo horrible! The three girls ganged up against our DD (who is an only child) and tried to leave her out of everything. It was really hard for her and even harder for us to see her go through it. But we just helped her get through it.
We told her that true friends don't treat their friends in that way. We also got her involved with a bunch of activities and I did a lot of crafts with her. Eventually, she became friends with another little girl, and they were together all the time this summer.
The old friend that dumped her noticed that my DD had a new friend and was not pressed to be with her or the other mean girls. Guess what? They want to be friends with DD again.

Now they all come over here.
It's really hard for DH and I to be kind to them; but we just told DD that she could see them, but suggested that she not trust them. She could forgive, but never forget what they did to her. I'd try to see this as an opportunity for your DD to open herself up to finding new friends. I figure it's a lesson they all have to eventually learn.
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