Johnmg wrote: She is stuck in the youth mind set that all there is to do is drink and party with anyone and everyone.
That's what young college students do. It's her time to not discriminate, and at some point she'll settle down. Let her make her own choices, good or bad.
It sounds like your upbringing was a rough one, so it makes sense you're vigilant about others (that's always a characterisitc of a child of an alcoholic).
I think you ought to back off from her and branch out on your own, find some activities, clubs, sports, something that occupies your time and opens up your world a bit.