Miskin Man,
Thanks for doing the alphabetized list. But I don't see Kate Wolf's name on it, or Stan Rogers's either.

I'd also add Jill Jackson Miller, who co-wrote "Let There Be Peace On Earth" with Sy Miller, whom she later married. Not sure if they're considered "folk," but I guess it depends on how broadly you define "folk."

I would also add Miriam Makeba to the list.