Here are a couple links with photos and information about Mary and the bands she has been a part of. Even more than her voice, I have envied her ability to be in bands with the coolest punny names: Howling Gael; St. Elmo's Choir; Broadside; Spinnaker --check it out.
The photos will certainly give you a sense of what Mary's like. I have sat up late with her at music gatherings, sharing a flask and singing filk songs about Valkyries in Valhallah (however you spell that).

http://nwseaport.org/archive.html
http://www.spinnakerband.com/index.htm

Blessings
Barbara