Most Helpful Guy
It means she is emotional and like many women, a little on the unstable side. Do yourself a favor, put distance between you and her and act like she never existed... and you won't get caught in her drama.
Most Helpful Girl
She's most likely jealous and a bit hurt. And by telling everyone else that the new guy is so "amazing" is to push it in your face so maybe you'll be jealous and maybe try fighting for her? I'm really sorry though. But in honesty it sounds like jealousy and she trying to get to you.