Mercy Sister Mary Joan (Joseph Marie) Lang, 90, died Jan. 6.

Born in Iowa, she followed her sister, Sister Mary Avellino, into the Sisters of Mercy, entering the community in 1957 and professing perpetual vows in 1965.

For more than 30 years, Sister Joan taught in various parochial schools in Park Forest, Des Plaines, Park Ridge and Chicago, as well as in Iowa. She also was assistant principal at Mary, Seat of Wisdom School, Park Ridge, from 1970 to 1978.

Sister Joan went into pastoral care in 1994, serving at St. Benedict Home in Niles. Six years later, however, she returned to teaching, serving as a part-time substitute at St. Angela. She stayed at St. Angela for nearly 15 years, teaching part-time as well as assisting as support staff.