In 1960, Sister Marie Ann was assigned to Hong Kong, where she taught at Maryknoll Convent School until her 1968 return to the U.S., where she earned her M.A. in Religious Education at St. Louis University in 1970.
Sister Marie Ann then made her way back to Hong Kong, setting to work again teaching religion and music to secondary school students at Maryknoll Convent School. She also directed a local parish choir during this time.
In 1972, Sister Marie Ann became one of the staff for the parish in Sau Mau Ping, a government housing estate. She lived at the Young Workers Center which was on the ground floor of one of the high rise apartment buildings, and worked in the parish from there. Living among the people there, the Sisters became aware of the need for better care for the elderly. At the same time, Bishop (later Cardinal) John Wu of Hong Kong asked for Sisters who would be willing to staff a Caritas home for the elderly in one of these government housing estates. Sister Marie Ann was one of four Maryknoll Sisters who responded to this need.
After three years of family ministry back in Minnesota, Sister Maria Ann returned once more to Hong Kong to continue work with the elderly. This was a ministry to which she would wholeheartedly devote herself for the next 20 years or more. Even after retiring to her mission in Macau, she ministered to the aged and infirm, visiting and ministering in numerous ways to their needs.
In 2005, Sister Marie Ann returned to the Maryknoll Sisters Center in Ossining, NY, to serve in pastoral care with the elderly and infirm members of her congregation until 2009. She continues to reside at the Center, where she is an active member of its Chi Rho Community.