If she goes the PSLF route, every single year she needs to get, in writing, that her employment that year qualified for PSLF.
If she wants to change jobs, get that it qualifies in writing before the job change. Keep multiple copies of that documentation in different locations, like a copy at a parent's house.
I don't know whether all that's possible, but from the horror stories I've read, I sure as hell would try to make it happen.
Alternatively, she could live like a pauper for 4-5 years and be done with them.