Cara,
Has she had a test run for diabetes? It is possible to be diabetic at that age. And I'm wondering about her diet. 20 something's tend to not eat well in order to stay thin.

I see where she has had a thyroid scan. Is her thyroid being monitored by a endocrinologist? The thyroid tests don't seem to be that reliable.

It does sound like neuropathy to me.

Billye