DD's in Y1, and according to her teacher is a perfect pupil (at parents' evening I had to keep checking that the teacher wasn't actually talking to another child's parents behind me )
At the end of reception the two classes were mixed up to balance up the social and ability mix - one class had been much more 'middle class' and had more very able children than the other class. The school did their best to keep established friendship groups together, although obviously they couldn't keep all the friendships in the same class. DD was moved up in a friendship group of 4, DD, two other little girls who I'll call X and Y who are also among the older girls in the class, and another little girl Z who's one of the younger ones. I was a little concerned about this as X's family had always planned to leave the school at Christmas and Z's childminder is Y's mum so obviously Y and Z spend a lot of time together. Y is very dominant and I was worried that once X had left DD would be left out on a limb as part of a 3. I'd been encouraging DD to branch out with her friendships especially after she was the only one of a much wider friendship group who wasn't invited to Y's party last year.
DD is already upset as it's X's last week at school and I've just found out that Y has not invited DD to her party again this year and DD is understandably devastated - if asked, she would always say that Y is her best friend, and when I've asked the teacher she says that DD and Y are constantly playing together and never seem to have any problems.
Should I say anything to Y's mum?