Sister Catherine, 54, founder of the Messengers of Love, a group devoted to uniting people of different races and religions, died of anemaia June 21 at George Washington University Hospital.

Sister Catherine was a psychologist by training and did much counselling among alcoholics, drug addicts and other persons in need as well as leading the Messengers of Love, which she started here about 10 years ago. She also was active in programs urging early detection and treatment of cancer and was a member of the board of directors of the Institute of Preventive Medicine.

She was born Catherine Hardy in South Shields, England. She began her religious life at the age of 16. From 1948 to 1952, she was a missionary in China. She later spent five years in Japan and then worked in France and Britain before coming to the United States in 1969.

Survivors include a sister, Elizabeth King, and five brothers, Charles, Terrence, Gerard, Dennis and Kevin Hardy, all of England, and a sixth brother, Brother Edmund Hardy, a member of the Blessed Sacrament Community in Wisconsin.

It was suggested that expressions of sympathy be in the form of contributions to Messengers of Love, P.O. Box 2740, Washington, 20013. CAPTION: Picture, SISTER CATHERINE