She began as a teacher working in various schools throughout the Archdiocese of Indianapolis and the Diocese of Evansville. She enjoyed the classroom and her students-but there was another career calling her so she left teaching and followed down a path that became near and dear to her.

Sister Mary Jonathan had a love for words and writing. She pursued a journalism career and became a proofreader for the Indianapolis Archdiocesan Catholic Newspaper, The Criterion. She then took a position with Abbey Press at St. Meinrad where she wrote many of their Care Note Booklets. She continued in this field until health problems forced her into early retirement and she came home to the monastery.