I think Marje has a good point about instruments. There is something special about women ballad singers in Scotland especially. I remember a session years ago at the National Festival where one after another got up to sing, and every one was a belter. Ray Fisher, Ellen Mitchell, Anne Neilson, were all there and all great. And I could add to that list Gordeanna McCulloch, Sylvia Barnes, Heather Heywood, Barbara Dymock, and Siobhan Miller. Perhaps they took their cue from Jeannie Robertson, Lizzie Higgins, Belle and Sheila Stewart, et al?

If you go back to the sources for the Child Ballads, or Cecil Sharp's Appalachian collection, you find that a lot of those ballads were collected from women too.