Sr. Claudette Zerfas, CSJ, formerly known as Dorothy Zerfas, died Monday, Jan. 10, in Kalamazoo. She was 91.

Dorothy Gertrude Zerfas was born Nov. 7, 1919, in Dorr to John and Clara (Weber) Zerfas. She was a member of SS. Peter & Paul Parish in Eaton Rapids at the time of her entrance into the Congregation of the Sisters of St. Joseph of Nazareth on Jan. 2, 1946. She received the name Sr. Claudette at her reception on July 2, 1946. She pronounced first vows July 2, 1948 and final vows July 2, 1951.

Sr. Zerfas earned a Bachelor of Arts degree in social science, English and Latin from Central Michigan University, Mount Pleasant, and she taught school for two years before she entered the congregation.

She earned a Master of Science degree in Mathematics from the University of Notre Dame.

Sr. Zerfas spent many years as a high school mathematics teacher in several schools of the congregation including St. Rita, Detroit; St. David, Detroit; Gabriel Richard High School, Riverview; and Muskegon Catholic Central High School.

She retired to Nazareth in 1991 and volunteered her time working in the General Office as a switchboard operator, driving sisters to medical appointments and scheduling car maintenance for all the house cars.

Sr. Zerfas is survived by two sisters, Bernice Sibal of Goshen, Ind. and Dolores Douglas of Winter Park, Fla.; two brothers, Gerald Zerfas of Kissimmee, Fla., and Ronald Zerfas of Lansing, as well as many nieces and nephews.

A funeral Mass was celebrated Jan. 14 in Holy Family Chapel, Nazareth. Interment was in Gate of Heaven Cemetery, Nazareth.

Memorials to Congregation of St. Joseph, 3427 Gull Road, P.O. Box 29, Nazareth 49074.