Grassing the poor girl up isn't going to help anyone. You all realise she is probably alcohol dependant. She probably beats herself up every morning when she wakes up in some guys bed - with a stonking hangover. And she sounds like fun. Why not take her under your wings, so to speak, look out for her, guide her away from one last martini for the road.
Look after each other ladies and gentlemen. The in-fighting gets you nowhere.