Mabel Edmund grew up north of Rockhampton in Queensland. Her father, John Mann was a descendant of South Sea islanders, blackbirded (from New Caledonia) to work in the canefields in Queensland. Edmund's mother was a Darumbal woman, Isabel Wallace. Mabel Edmund received schooling until she was 13 and then was sent by her parents to Bombandy cattle station to work. Two years later her mother died and she married Digger Edmunds. Their marriage lasted 35 years, until Digger died from a heart attack.
Edmund became involved with politics as a young woman. In 1968, she joined the local branch of the Australian Labour Party (ALP), and for many years she was the secretary-treasurer of the Nerimbera ALP Branch. By 1970, she was elected to a seat on the Livingstone Shire Council, she remained there for six years.
In the 1970s the Aboriginal and Torres Strait Islander Legal Service (ATSILS) opened in Rockhampton. Edmund became heavily involved with ATSILS, first by joining the local district committee then later by holding the positions of district president, state councillor, and state secretary. Besides her work for ATSILS, she was nominated by the governor-general to work on the Aboriginal Loans Commission. In addition to her political work, she worked as a model on television to help provide an income for the household.
Suffering grief after the death of her husband, Edmund decided to move to Cairns and attend the Aboriginal and Torres Strait Islander Art School. After two years of study, she graduated in 1986. She held her first art exhibition in 1987, and was asked to come back again the following year. In 1989, Edmund held a joint art exhibition with the students of the Aboriginal and Torres Strait Islander Art School.