Sister Miriam Leonard Howeiler, S.C., who served as principal of three schools in the archdiocese, died Aug. 26 at St. Joseph's Medical Center, Yonkers. She was 99. She was principal of Our Lady of Good Counsel School, Manhattan, 1948-1954; St. Ignatius Loyola, Manhattan, 1954-1958; and St. Mary's, Yonkers, 1963-1972. She also taught in Manhattan at Holy Trinity, 1929-1930; St. Paul's, 1930-1940; and St. John the Evangelist, 1944-1948; and in Mamaroneck at Holy Trinity, 1940-1944. She was a council member of her congregation at Mount St. Vincent, the Bronx, 1958-1963; administrator of Mary the Queen Convent, Yonkers, 1972-1981; a substitute teacher, 1981-1983; and receptionist at the Fordham Jesuit Community in the Bronx, 1983-1996. She volunteered at the Sisters of Charity Multi-Service Center in Yonkers, 1998-2002. Born in Manhattan, she entered the Sisters of Charity in 1927 and professed final vows in 1933. She held a bachelor's degree from the College of Mount St. Vincent, the Bronx, and a state certificate in nursing home administration. She is survived by a sister, Kathryn Forderhase. A Funeral Mass was offered Aug. 30 at St. Mary's Church, Yonkers, with burial in St. Joseph's Cemetery there.