Born deaf at Headingly, MB. Attended a local school for the deaf in downtown Winnipeg 1888-graduation 1902; her hearing father, William Thomas Lonsdale, was instrumental in the establishment of what later became the Manitoba School for the Deaf, though too late for Mary. She attended Gallaudet College and became a teacher for the deaf, first briefly in 1911 at the downtown Winnepeg school and then at the Manitoba school from 1912 until her death in 1936. Also active in local efforts to improve the lot of the deaf.
Deaf Women of Canada, p.152.
1878-1 October 1936