Although Lucinda Williams has been the most prominent female flag bearer for the Americana genre, I strongly suggest you also pay attention to Mary Gauthier, if you haven't already done so.
The 55-year-old's back story is fascinating. Adopted as a child, she became a street kid runaway and fell seriously into drugs and alcohol to deal with the fact she was abandoned by her birth mother. She then turned her life around, eventually running a Cajun restaurant in Boston for 11 years.
At age 30, music also sent her a calling card and by the mid 90s, she lived her life in both domains.
She didn't write her first song until she was 35.
From the release of her second album, 1998's Drag Queens in Limousines, she has devoted her life to music and garnered a loyal following, playing major festivals, and releasing 11 albums.