Yiiiikes, she sounds like a real trainwreck. Hopefully she gets her shit together before she's too old.
The best thing I ever did was decide I can't fix anyone and stop taking that responsibility on myself. It's hard at first, but it's really really nice. It helps that my SO is a great dude, but I met him literally after I decided I was no longer interested in broken people. Good luck to you! Sounds like you're in for a heck of a time (getting masters, single, lots going for you, no longer picking up project people) git it!