Can she begin by seeing an MD? I know that you never fully recover from a loss like this, but it sounds like her grief has become depression. Antidepressants may help her function. Are there any support groups in your area? Even a site like this can be helpful.

We lost my father 5 years ago (seems like yesterday). My mother has been bipolar for as long as I can remember, prone to deep depressions and suicidal tendencies. We were very concerned about her when my dad died. But with the help of medication she's been able to continue functioning.

It is so nice that you care so much about your friend.