Sister Benedicta McWeeney, S.A., a sacristan at the motherhouse of the Franciscan Sisters of the Atonement at Graymoor in Garrison, died March 19 at Hudson Valley Hospital in Cortlandt Manor. She was 81. She was a sacristan at the motherhouse from 1988 until her recent retirement. She had served in ministries in other U.S. cities and in Canada. Born in County Leitrim, Ireland, she entered the religious community in 1945 and professed final vows in 1954. A Funeral Mass was offered March 26 in the motherhouse chapel, with burial in the sisters' cemetery.