Mildred Thompson Little Johnstone was born in 1906 in Kensington, Prince Edward Island. Mildred attended the Prince Edward Island Hospital School of Nursing in Charlottetown and graduated as a registered Nurse on May 12th, 1930. For years she practiced as a private nurse, traveling to communities across Prince Edward Island to help those in need. Upon the completion of the Prince Edward Island Hospital on Brighton Road she became the Night Supervisor and she spent her career there highly respected by colleagues and students alike.
In 1957 Mildred married Harold Little of Nova Scotia, who died suddenly in 1959. Upon his death Mildred returned to nursing in Charlottetown and married again in 1961 to William E. Johnstone of Long River. The two lived in Kensington until his death in 1989. Mildred again returned to Charlottetown and resided on Belvedere Avenue, her home for the remainder of her life.
Mildred died at the Queen Elizabeth Hospital on September 20th, 1996 at the age of 90. She was a member of many local organizations; the alumni of the Prince Edward Island Hospital School of Nursing, the Kensington U.C.W., the Rose Show Society, the Abegweit Branch of United Empire Loyalists, the Rebecca Lodge, the Business and Professional Women's Club of Charlottetown, and the Heritage Foundation. She was also an avid historian and genealogist.