Sister Mary Regis was involved in elementary education for many years. In New York, she taught at Saint Patrick School in Newburgh NY (1956-57), Regina Coeli School in Hyde Park NY (1967-69), and Holy Rosary School in Hawthorne NY (1972-85). In New Jersey, she taught at Saint Joseph Elementary School in Toms River NJ (1958-67), and Saint Anthony School in Hawthorne NJ (1970-72). In 1985, Sister went to work for the Marist Brothers in Bayonne, New Jersey, as assistant to the provincial treasurer, and remained there until 1990. She was coordinator of the Nazareth Community of the Dominican Sisters from 1990-92 and assistant to the treasurer of the Dominican Sisters of the Sick Poor in Ossining from 1992-95. From 1995 until her death, Sister Mary Regis was a clerk in the finance office of the Dominican Sisters of Hope.