Born in Charleston, South Carolina, her family later settled in south St. Louis. She entered the Sisters of the Most Precious Blood after graduation from St. Elizabeth Academy. She was received into the novitiate in 1958 and received the name Sister John Mark. She professed first vows in 1960. She earned a bachelor’s degree in elementary education at Fontbonne College and a master’s degree in creation spirituality from Holy Names College in Oakland, California.

Sister Margaret served as an elementary and preschool teacher in Missouri at All Saints in St. Peters; St. Brendan in Mexico (Missouri); Assumption in Mattese; St. Paul in Fenton; Linda Vista Catholic School in Chesterfield; St. Clement of Rome in Des Peres; and Visitation Child Development Center and Most Holy Trinity School in St. Louis.

She served for five years as a residential counselor at Girls Hope in St. Louis and for two years in ministry to the poor at Genoa Christian Center in West Virginia. Since 2005, Sister Margaret ministered in massage therapy and pranic healing with Dr. Joan Brower in Wentzville.

Survivors include her brother, Dan Bollner.