I think it is very normal for friendships to change at this age as friends realise that they are simply growing away from each other. Most people acquire new best friends at various stages of life and the move to secondary is a typical such stage ime (as is starting university). I would be comforting if your dd is upset, but reassure her that this is normal.
I get the vibes that maybe Y was with adults who could only spare the time to visit X (or drop her off to see X). That would make it embarasing for Y who does not know what to say to your DD now that X has let it out of the bag that they met up. Don't take anything to heart as the visit to your town was not for the purpose of the kids meeting up, that was just a bonus for Y. These days with the internet etc friends may be 100miles away but are still close. As they grow older they could in future spend whole weeks at each other's houses in the holidays or when older still even end up at the same college or uni or even work together in the future. Just encourage them to stay friends and never ..... NEVER ... say anything negative about their friends to them (unless it is well deserved like if they rob a bank or something!) as it always comes back to haunt you and may alienate your DD from confiding in you if she misses her friend. I am pleased to hear that your DD loves senior school and you sound like a very loving mum btw so your DD will have a happy life. xx
DD has just moved up to secondary school and absolutely loves it. She has made loads of friends and is just having a ball however I feel really annoyed about her old friends.
Her 2 closest friends from pirmary go to 2 different schools but X lives locally (5 minutes away) and the other girl (lets call her Y) has moved away (a long way away ie over 100 miles away but has family in the area).
DD was closer to the girl that moved away Y and has been in constant communication via email, text and skype with Y over the summer and since school has started.
Last week DD bumps into X who says "oh, Y is coming down next week". DD thinks nothing of it as she assumed that Y would have told her since she was in constant communication with her.
DD sees X yesterday morning and X doesn't say anything to her about Y visiting again. We get to yesterday afternoon and Y sends DD a message saying "I saw X today!". Now, given that X and DD live 5 minutes away and Y was in the area visiting family yesterday and made arrangements to see X but not DD, am I overreacting to feel angry and upset for DD that 1 of her 2 closest friends was in the area and didn't bother making any effort to see her and then thinks its okay to send a message like that?
DD dealt with it very well and sent a message back saying "oh" and then ignored further messages from Y which were an attempt to engage in conversation.
The ridiculous thing is that X and her mother will never ever make any effort to visit Y in the future however as we have some family near where Y lives, we were planning to visit next time we were there.
Again, am I overreacting to want DD to have nothing more to do with Y and not contact her again?