Kinnie Star.. she Rules!!!
Also, Zero 7. They have some great female singers on their songs
Bebel Giliberto-Beautiful singer, daugher of Astrud Gilberto
Don't forget all the jazzy greats like Nina Simone, Billy Holiday, Ella Fitzgerold, Etta James
Cibo Matto for some wierd japanezy stuff
Also.. if your into sorta RnB singers, India Arie, Jill Scott and Eyrkah Badu