If you don't know Cowboy Junkies, definitely worth a spin, as Qdrone says. I might start with Caution Horses, but lots of nice stuff, like Miles from Our Home (but note the music runs to a fairly homogenous sound, across discs).
Other female vocals:
Kasey Chambers, "Barricades and Brick Walls," "Wayward Angel"
Stacey Earle, "Simple Gearle" (Yes, Steve's sister, I think)
Gillian Welch, "Time"
Wailin Jennys, "40 Days."
Robinella, "& CC String Band"
Lucinda Williams, "Carwheels on a Gravel Road" (!) (!)
All the above alt.country-ish.
A lovely jazz voice now starting to be heard nationally belongs to Erin Bode (erinbode.com), as on "Don't Take Your Time"
jmd
