The daughter of John and Elizabeth Mattingly O’Reilly, Margaret was born Nov. 28, 1902, in Hardinsburg, Ky. She received her elementary and some secondary schooling at St. Romuald School there and later attended Mount Saint Joseph Academy. When she was 21 years of age, Margaret entered the novitiate at Mount Saint Joseph. Following a seven-month postulancy, she received the Ursuline habit and the name Sister Immaculata on August 15, 1924.
Sister Immaculata was prepared to teach music. In 1925, she was assigned to St. Peter School at Waverly, Ky., where she taught for seven years. Her next assignments took her to St. Bernard Academy in Nebraska City, Neb., for four years, St. Ann School in Howardstown, Ky., for two years, and St. Angela Home in Louisville for eight years. In 1946, she was elected to the office of mother assistant and in 1948, was elected to the office of mother superior. During her term in community leadership, the community celebrated the diamond jubilee of Mount Saint Joseph Academy, and Mount Saint Joseph Junior College moved off campus to open as Brescia College in Owensboro. Following her term as mother superior, Sister Immaculata served one year as assistant in the treasurer’s office before returning to teaching music and serving as parish organist. She was missioned in Kentucky to St. Raphael in Daviess County, St. Margaret Mary (Lyndon), Stanley, Buechel, St. Denis (Shively) and Mother of Good Counsel (Louisville).
Sister became very ill while at Mother of Good Counsel. She had suffered from a long-standing heart condition. She returned to the Motherhouse in late November 1967, was admitted to Mercy Hospital in Owensboro and died on December 2, 1967.
Msgr. Albert Thompson, chaplain, and Father Bernard Powers, associate chaplain celebrated the funeral Mass. Sister Immaculata’s remains are buried in the convent cemetery.