My DD is having a few problems atm she is 14 and ofcourse its usually about a boy.lol

Anyway to put a long story short a good friend of hers is giving her hard time about a particular boy that apparently they both like but he likes my dd, the problem is she is now calling my dd awful names and making up stories etc about her. I just read dd's facebook status and i thought i better go see if she is ok I just found dd in her room crying, she says she isnt but us mothers know better. We had a chat and she said her friend jsut text her calling her a S**t, which those of you that know her is far from the truth.

I am finding it hard to ignore it as she is obviously very upset but on the other hand i know that it will probably make things worse for her.
Would you stay out of it or talk to her friend?