Mary Frances Dunn was the eldest child of John Dunn (1838-1924), a stonemason of Dunn & Williams, monumental marble works of Brisbane Street, Launceston, and Catherine (Kate) Agnes Warren (1854-1940), who were married in New Zealand in 1872. Mary was born in Greymouth, New Zealand, on 26 Jan 1873.
The family moved from New Zealand to Victoria where their three sons, Thomas, John Christopher and William, were born. They later came to Tasmania where John Dunn started business as a stonemason in 1883. Their daughter Winifred was born in Launceston in 1888.
Mary Frances died of diphtheria on 24 Jan 1894, just two days before her twenty-first birthday. She was buried at the Catholic Cemetery, Connaught Crescent.