15 yo DD is really upset about a friendship breakdown. She has been friends for years with Girl A and Girl B and they went around as a threesome. B recently began ignoring DD and being offish with her. DD is shy and unassertive, and didn't feel able to speak up about it. Last week, Girl A also said to DD that she didn't want to be friends anymore. She has since apologised, but DD feels totally betrayed and left out. She spends breaks and lunchtimes alone. DD refuses to talk to a teacher, talk to Girls A and B, or ask other groups if she can join them. She won't allow me to do so either. I hate to witness what this is doing to DD, but I feel completely helpless. Any thoughts?