The arm is usable (just weak and she has trouble grasping things) and there's no pain. I saw her today and it seems like the majority of the trouble is in her ring and pinky fingers. She demonstrated that on her right hand she can stretch her fingers apart and resist a force pushing her pinky finger back towards the other fingers, but on her left hand that finger offers no resistance at all.

I've learned a bit more...evidently the neuro has just declared it idiopathic neuropathy, and has suggested that in the meantime until the next set of tests that my friend do stress ball exercises, etc., to try to keep working the muscles in that area (which I've heard is a good idea).

I'm going to suggest to her that she at least keep in mind the possibility of getting a second opinion and an MRI. (Evidently she had one about a year and a half ago but I'm guessing that wouldn't have necessarily showed anything manifesting now). I think partially she doesn't want to spend the money if she's not sure it will show anything, but at least the option will be on the table.

Thanks again, all, for your help.