"Bonny Fechters: women in Scotland, 1900 - 1950" by Sheila Livingstone, Scottish Library Association, 1994. ISBN 0 900649 89 5.
Out of print, as far as I can see. Should be available second-hand online: try ABE.

I forgot to say that Mary's parents were Rosie (nee Brown) and Sandy Soutar. In "Sidlaw Breezes", there a nice pic of them and Mary, along with nephew Fred Soutar and his accordian, celebrating their Golden Wedding (50 years) in 1948. If any one would like a copy just PM me an email address. Also, Mary was one of 10 children - many of whom did't survive infancy.