Born in Brooklyn, Sister Mary Donald was orphaned at an early age and was raised by her aunt and uncle. She attended St. Jerome School, East Flatbush, and Mercy Juniorate H.S., Fort Greene.
She entered the Sisters of Mercy Novitiate in Syosset in September 1946 and professed her final vows in March 1952.
Sister Mary Donald received a bachelor’s degree in English from St. Francis College, Brooklyn Heights, and taught at the following schools: St. Gregory, Crown Heights, 1949-51; Sacred Heart, Fort Greene, 1951-53; St. Patrick, Bay Shore, 1953-60; St. Pius X, Plainview, 1960-63; St.Therese of Lisieux, 1963-68; and Holy Innocents, Flatbush,1968-74. She was a guidance counselor at Mercy H.S., Riverhead, L.I., 1974-98. After retiring in 1998, she continued as a volunteer to support staff at McGann-Mercy H.S. in Riverhead until 2010.
A Mass of Christian burial was celebrated in Sisters of Mercy Convent, Whitestone. Burial was in St. Charles Cemetery, Farmingdale.