DD recently had her first sleepover with three of her friends. I had had reservations about one of the girls DD had invited (lets call her Anne), as when she has been to our house previously I've noticed her to be slightly bossy and dominant. Everything has to be her way, she'll sulk if she doesn't get it etc. For these reasons I have to say I've not been making much of an effort to invite Anne round, and in fairness DD hasn't made too much of a fuss having her round.
Anyway, so noticed over the course of the afternoon and evening, Anne was singling out one of the other girls (lets call her Bea). DD has been friends with Bea since the beginning of primary school, and DD and Bea get on amazingly. Negotiate between themselves, don't argue and when Bea is here or DD is at Bea's house, you wouldn't know they were there. But throughout the afternoon, playing games Anne would say "oh Bea you'll go last you don't mind" but it wouldn't be a question it would be a statement or an order. There was an argument about where they were going to sit in the restaurant and Bea lost against Anne as well. There were other things but I can't think of them at the moment but I intervened a few times to let Anne know exactly who was in charge (she tried to undermine me when the third girl in the group asked me to do something and Anne chimed in and told her no she couldn't to which I replied "I'm in charge here, regardless of whether she can or can't do it, she asked me and it is my decision not yours".
So, I was talking Bea's mum when she came to pick her up, and I said that Bea was lovely and welcome anytime as usual, but did say I'd think twice about having Anne again as I felt she was in the middle of all disagreements and more trouble than the friendship is worth. Bea's mum did say similar and that she hadn't had Anne over for a long time due to her dominance over Bea.
Speaking to a totally unrelated third party over lunch one day, he pointed out that Anne was essentially picking on the weak one in the pack (I had made the comment that DD and other girl who was there can hold their own against Anne, but Bea is not very - can't think of the word but strong/confident). I realised he had made a very good point and it was like that for the weekend, in that Bea was singled out or excluded. A couple of times as well DD and other girl stood up for Bea.
To end this horrifically jumbled mess, would you tell Bea's mother that you're concerned as Bea and Anne are in the same class together? Or stay out of it as it's none of my business (girls are 7 by the way). I just feel that in my experience so far with DD there's more than just normal squabbling between Anne and Bea.