Why does my friend vent on FB but not to me?

seems to me, its venting she wants, that or some one to cry on and not give her a pep talk but cry with her. not saying that's what you should do, if that's not who you are, be the friend, you want to have, or the friend you naturally are. and let her be her, don't try to compromise.what you compromise to keep, you lose. she prolly just wants to tell her story.