I was going to suggest a playdate too, and get to know some of the parents if you can. When they see us socialising in their environment it really does help with their confidence and it helps the other kids too strangely. I think it can take a while. I know this from having moved around a lot as a child and switching schools. Sometimes you just click with some people and other times it can take at least 6 months, especially if the social groups are close nit.