You have to trust that if she was socially successful once, she will be again. My oldest went through this, spent most of his second semester holed up in his room. Being a typical boy, he internalized it all instead of venting to us. Counseling did help, in his case the summer after freshman year away from the drama.
Now, a first semester junior, he is back to his Van Wilder ways with mostly a new group of friends. Lucky for us, the younger ones avoid all this by being total nerds.