Firefoot is scottish. And male, actually. I'm aware that makes no sense to describe the voice of a Midwest female, but due to Firefoot's tendency to play male RPG characters (sorry, but y'know - Siamak is one particularly who will always stick in my head); she has a kind of soft glaswegian accent - think Fran from Travis
(It's a compliment. Really.)
Bethberry is another who has a rather distinct voice: Sarah McLaughlin, whose voice I love (When She Loved Me - aww...). However, I have no idea how Ms. Mclaughlin sounds when speaking, so imagine that singing voice speaking...