Sister Margaret Mary was born in Chicago, Illinois, on May 10, 1931. Her parents were Frank J. and Marie (Jedlicka) Schima. She attended Catholic Schools, Our Lady of Victory in Chicago and St. Barbara in Brookfield where they moved in 1937. In both schools, the religious, Sisters of St. Joseph of St. Francis in Chicago and the Sisters of St. Joseph in Brookfield, were an influence on Margaret in her call by God to religious life. After attending high school at Sacred Heart Academy in Lisle, Illinois, Margaret answered God’s call and entered Sacred Heart Monastery in Lisle on July 2, 1949. Again, it was the Sisters, Benedictines at Sacred Heart, who had a strong influence on her, especially with their daily prayers in the Divine Office.

On June 24, 1950 she began her novitiate year and received the name, Sister Mary Assumpta, O.S.B. One year later on June 25, 1951 Sister pronounced first vows and on June 25, 1954, perpetual vows.

There were several ministries assigned to Sister Margaret at Sacred Heart: Sophomore Advisor and teacher at the Academy in Lisle; teacher, then principal at St. Vitus School in Chicago for nine years.

In August of 1961 she was assigned, another call from God, to Warren, Ohio as Principal and Superior at SS. Peter and Paul School. This was a Byzantine Eastern Rite School and Parish. In August of 1962, the Parish High School began. A few years later in March, Sister was sent to St. Mary of Celle in Berwyn, Illinois, as Principal and Superior. The following August she returned to Warren to continue as Principal of SS. Peter Elementary and High School Principal (for seven years).

In June of 1965 all of the Sisters of the Byzantine Rite who had previously entered Sacred Heart Convent in Lisle, Illinois, were sent to the mission in Warren, Ohio, for a probationary period of time. On February 2, 1969 the Lisle religious community formally established the Foundation for Queen of Heaven Monastery of the Byzantine Church. Sister Margaret Mary Schima was elected the first Prioress. She served in that position for twenty-one years and Administrator of the Monastery for seven years, for various terms of office.

Sister’s higher education began with Jaeger Junior College and St. Procopius College, both in Lisle, Illinois. Attending DePaul University in Chicago, for several years, Sister received a Bachelor degree in February of 1962. John Carroll University awarded Sister with a M.A. Degree in August of 1965. On July 19, 1979 Sister earned a Doctorate degree from Walden University in Florida.

On November 21, 2010, Sister Judith Ann Heble, O.S.B., Prioress, and the Lisle Community accepted Queen of Heaven Monastery as a dependent monastery of Sacred Heart Monastery. Sister Margaret Mary was appointed Administrator.

In 2013 Sister Margaret Mary returned to the motherhouse at Sacred Heart Monastery in Lisle, where she continues to set up the archives of Queen of Heaven Monastery.