Mary Joan (Mullally) Bradley was born in 1911 to James and Margaret Mullally. She was the youngest of three children and had two older siblings: a brother named Carroll (b. 1904) and a sister named Mary (b. 1908).

Mary grew up in Souris, Prince Edward Island. As a young woman she went to Charlottetown to study nursing. She graduated from the Charlottetown Hospital School of Nursing on 1 September 1937. At that time she was working at the Provincial Sanatorium and remained there until her marriage to Robert E. Bradley on 3 August 1938. Mary then left nursing and moved with her husband to 122 Hillsborough Street in Charlottetown.

With the outbreak of World War II, Mary went back to work. From 1939 to 1945 she did private duty nursing at both the Charlottetown and Prince Edward Island hospitals. Mary and Robert purchased their first home during this period, and moved into their house at 93 Upper Queen Street in 1942. In December 1945, Mary went to work at the Charlottetown Clinic and remained in this position until 1960. On 1 September 1987, Mary celebrated the golden jubilee of her graduation from the Charlottetown Hospital School of Nursing. The Class of 1937 reunion included a mass at Mount St. Mary's Chapel, a luncheon at the Inn on the Hill, and a banquet at the Charlottetown Hotel.

In addition to her nursing career, Mary also helped her husband Robert run their family business. In October 1952, Robert Bradley and Joe McKenna opened the Charlottetown Funeral Home. Mr. McKenna left the business shortly after it opened, and Robert and Mary ran the funeral home until their retirements in 1978. Their nephew, Francis J. Bradley, who came to work with them in 1960, continues to work as a funeral director at the Cutcliffe, Charlottetown, and Hennessey Funeral Homes.

Mary died at her home in Sherwood on 25 November 1994 at the age of eighty-four. She was buried with her husband Robert (d. 1979) in the People's Roman Catholic Cemetery in Charlottetown.