im at a loss

I would avoid seeking help from their GC members. You've already contacted their nationals, so unless someone GC sits on nationals, then they won't be of much help. Plus, you want to keep it as private as possible to protect her identity.

I would also try as hard as possible to have her GET OUT and have her contact the appropriate authorities as well -- nationals, the university, even the police -- because it sounds like she's in danger if she's depressed and scared all the time.

I know she's terrified, but progress might be made if she contacted them herself.