Mary Terszak was born at Moore River Native Settlement, the daughter of Gyce Woods and Elizabeth Clare Woods (nee Khan). Terszak was removed from her family's care at Carrolup Mission in 1944, at the age of two, and sent to Sister Kate's Children's Home where she lived until 1962 except for time spent at Home of the Good Shepherd - a girls' reformatory - circa 1953-1954. Terszak was only reunited with her mother and other family members in 1989.
Terszak holds a Master of Arts in Indigenous Research and Development from Curtin University.
Her story was recorded by the National Library of Australia for the Bringing Them Home oral history project and appeared in the associated publication Many Voices: Reflections on experiences of Indigenous child separation, edited by Doreen Mellor and Anna Haebich (2002) and she has published exerpts from her diaries as well as reflections on her life as a member of the Stolen Generations in the book Orphaned by the Colour of My Skin.