Wishing for understanding is normal. I don't think there's a hard and fast explanation yet, as has been stated.

Educating yourself regarding the subject would be helpful. Listening to your child and her friends will be helpful, too.

I can only imagine how tough it can be to keep up with "who is who"! Perhaps a list on the frig and ask your daughter's friends to help you with it. Asking them for help in a genuine way can offer much respect and love.