If you have a DC at private school, do they have friends who they really like, talk about, go out with at school, chat to or see in the holidays?
DD has moved from state to private for Sixth Form and says not many engage with eachother (not her personally) and she's finding this hard. Classroom sizes are tiny in Sixth form reducing the chance of making friends through interests, so there isn't much scope for friends there. She knows she can't expect to make friends straight away. It maybe that she's just used to being at a large school where they'll be always lots of pupils to engage with and, therefore, if you don't get on with some, there's still somewhere to fit in and be yourself.