Eileen O'Sullivan was born in Knockavullig, Killinardrish, Co. Cork on September 27, 1923, one of a family of six, three boys and three girls. She grew up on the family farm and attended Canovee NS, Convent of Mercy, Macroom, passing her Leaving Certificate examination there in 1942. She continued to study Latin for her Matriculation which she passed the following year.

Eileen entered in Cahiracon on August 1, 1947 and was received into the congregation on February 25, 1948, taking the religious name, Sister Mary Margaret. She made her First Profession on March 17, 1950. In October of that year she went to study in Dublin, first in University College where she completed a pre-medical course and then in Colaist Muire le Tios in Cathal Brugha Street, obtaining a certificate in Household Management in 1953. She was assigned to Silver Creek, New York where she worked in the catering department of the Columban Fathers' seminary for a year but she was recalled to Dublin in 1954, having beer appointed sister in charge of the community in the House of Studies in Merrion Square.

In 1956 she resumed study in University College, Dublin taking a course in radiography and after obtaining her M.S.R. in 1959 she was assigned to Hong Kong. She served a~ radiographer in the Ruttonjee Sanatorium until 1968 when she was appointed superior of the community in Sandy Bay where the Columban Sisters administered the Duchess of Ken Children's Orthopedic Hospital. In 1970 she was appointed superior of the community in Ruttonjee, a position she held until 1972.

She continued her service as radiographer in the Sanatorium and showed deep concern for the staff and the patients. She also took an active interest in the growth of the Church in Hong Kong, participating in the work of many Catholic organizations and, for a time, she represented the Columban Sisters on the Diocese Council.

In November 1984 she became ill and was found to have cancer. She accepted this diagnosis serenely and came to Ireland for treatment but the disease acted rapidly and she died in Magherarnore on January 30,1985. She is buried in the cemetery there.

Sister Mary Margaret was a single-minded and dedicated religious always ready to give herself totally to whatever task she was assigned. A woman of deep faith and unfailing kindness.

Her motto was: Jesus, not my will but thine be done.