Cleo Woodard Gaynor, 56, a retired principal of the Cedar Knoll school at the D.C. Children's Center in Laurel, died of a heart attack Feb. 14 at a hospital in Portsmouth, Va.

In about 1950, Mrs. Gaynor joined the staff at Cedar Knoll, the city's facility for delinquent children, as a typing teacher. Before being named principal she had been the school's music instructor and an assistant principal. She was principal of the school when she retired in 1976 for medical reasons.

She had worked for the Interstate Commerce Commission here before beginning her career at Cedar Knoll.

Mrs. Gaynor was born in Portsmouth and taught school in Norfolk before moving to Washington in 1945. She returned to Portsmouth last year.

She earned a bachelor's degree in public school music from Virginia State College in about 1944 and did graduate work at the University of Maryland.

She served as organist and choir director at the Randall Methodist Church in Washington for more than 18 years. She also was active in the Whifipi Music Club, an organization of local musicians of the 1950s and 60s.

Survivors include her husband, Edward Sr., of Washington; a son, Edward Jr., of Landover; her mother, Elise M. Woodard, of the home in Portsmouth; three sisters, Agnes Wilson, of Arlington, Carolyn Woodard, of Pisgah, Md., and Frances Jones, also of Portsmouth; a brother, Charles Woodard, of Silver Spring, and a foster brother, Michael Elliott, of Detroit.