Marie Hart was born in Western Australia, perhaps at Collie, but was removed from her family as a young child and never met her parents or siblings again. Hart may have been at Carrolup Mission before being sent to Sister Kate's Home at around five years old. Hart's files from her institutional years show that her parents repeatedly requested the return of their child but were refused and that they were required to pay maintenance for her residence at the Home. After leaving the Home, Hart worked on farms then moved to Sydney and lived there and in north Queensland. She returned to Western Australia to search for her family.
Hart's 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).