Well, the vet. dermatologist confirmed that Zoe does have ringworm.
It's apparently an odd case, as she does not have any red spots or sores, scabs, etc. She's not even itchy. Just balding.
So far she's had two lime sulpher dips (while we were waiting on culture). She will continue those, receive a pediatric, liquid, anti-fungal med. Since she's so small (2 1/4 lbs) she has to take one week on, one off, one on, etc. He recommended I cut short what miniscule amount of hair she does have, and that we clean with bleach, vacuum, etc. continuously. Apparently this can take many months to cure (or not...go, Zoe, go:exclaim...you can do it...knock this out in a month!).
Bummed. Especially for poor tiny Zoe, who's had such a rough go of it!