Sister Kathleen Leary was born on February 8, 1945 in Boston, the daughter of Francis and Anna (Harrington) Leary. She entered the Sisters of Notre Dame de Namur in 1963, taking the name Sister Ann St. Francis. She took her first vows in 1966 and final vows in 1971.
After entering, she taught first grade at Holy Rosary in Lawrence, Mass., from 1967 to 1969. After this, she taught at Our Lady, the Comforter of the Afflicted [OLCA] in Waltham, Mass., from 1969 to 1971, St. Monica in Methuen, Mass., from 1971 to 1973. Then, she began to teach at St. Augustine's in Andover, Mass., where she continues to work until this day. In addition, she also has worked at the Asian Center in Lawrence with children.