Another find (at least to *me*) in the category 'great female voices of the 60s' is Joan Toliver doing songs in a Judy Henske / Karen Dalton / Barbara Dane / Judy Roderick vein like 'High Flying Bird', 'Black Crow Flying', 'Wayfaring Stranger', etc. On her first (?) album Bruce Langhorne does a great job as arranger/guitarist.
As I (again) tried to gather the (few) facts I know about this lady in a discography (adding some sound clips) at http://www.wirz.de/music/toliver.htm I appreciate any additions/corrections !!!