This happens SO much now a days. Bri, your right. Your friend DOES have a right to know, that this girl is talking about her. Tell your friend that this person is talking about her, but tell her not to say it was you who told her. Then you won't need to be involved with the whole conflict. Maybe these two people can talk it out and move on, or just maybe they were not ment to be friends. Do you know if their both in a fight about something? If that's the case, stay out of it. If not, tell your friend about this person talking about her. That's what I would do, and I HAVE done it before.