Hi beckybee23
Just posted to someone else about much the same thing, which she described as bullying. My feeling is it's a 'controlling game' girls play and really the trick is to learn to ignore it.
Our ground rules with DDs are these:
Everyone in your class is a friend
Treat everyone well
Don't tease other students
Help out younger children
DD2's class has a great deal of weird goings on about who can play with whom and when. They actually arrange play dates for break time. I think the teachers are mad to be fostering this - because the reality is that two girls always insist on who plays with whom and run the show.
We've dealt with it by explaining what DD2 can do when she can't play with someone she wants to: read a book, draw on the playground with chalks, play on the climbing frame, ride a scooter, etc.... We've also encouraged her to include others in whatever playing she's doing.
The end result is that DD2 is the kind of child that people who are being excluded or don't want to play whatever (football, tig, etc...) just gravitate to. She enjoys quiet play (like gathering leaves and flowers and making a drawing out of them on the playground) and others have realised she's a nice, quiet girl to play with when they want to.
So my advice is take the attitude this kind of thing happens and the best protection is to arm your child with alternatives, when she can't play with the children she wants to for whatever reason.
HTH