MacDonald held the title of Matron-in-Chief of the Canadian Army Medical Corps Nursing Service, the first woman promoted to the rank of major in the British Empire and was awarded the Royal Red Cross (1916) and the Florence Nightingale Medal (1918).

Her father was a store owner and provided MacDonald the opportunity to receive an education from an early age, atypical for girls of that time.

Between 1868 and 1879, Mary Elizabeth gave birth to eleven children, nine of which survived into adulthood; six girls and three boys.

Both of her parents descended from the Scottish highlands and her great-grandparents made their way from Scotland to Nova Scotia in the late 1700s.

This store was the area's only source of farm products and imported goods from Montreal, the United States, and Great Britain.

MacDonald received a good education for a girl of the time period, including reading, writing, arithmetic, geography and grammar.

Soon after, MacDonald also served as a nurse during the South African War in 1900, where she was one of the first women to receive a military commission.

[1][2] After her involvement with the South African War, MacDonald returned to Canada, where she was soon named the head nurse of the Canadian Army Medical Corps.

[2][3] MacDonald returned to Canada in 1919, and was soon named the head of the Nursing Service of the Canadian Army Medical Corps.