I just find everything with her at the minute very odd.
If things really are that bad then why doesn't she move home to her parents. Ask them to support her while she finds whatever it is she needs to find, Her feet, her head, whatever. Most parents would do that if their child was in need. She's flogging a dead horse by getting treatment, ignoring treatment rinse and repeat as per instructions.
If money is tight that things are a struggle and the bills are piling then going home will help eliminate some of the debt by enabling it not to increase. She could seek out citizens advice to work out a payment plan or declare herself bankrupt and start over again.
Burying her head in th sand is never a good idea. I know it or was me I would move home, hit the job centre and start digging my way out. I couldn't live like that.
If her depression is just because she cannot do he job, then find something new. I hate the way people just state, I can't!
I worked my arse off for years to get my education and even now I would go out and do something if I felt it needed doing to further my career. I CANT is not an excuse, try and you might!