A native of Fancy Farm, Kentucky, she was born Mary Ernestine Hayden, the daughter of Felix and Ethel Veronica Buckman Hayden.
In the Diocese of Owensboro, her ministry included St. Anthony Convent, Browns Valley (1936), and St. Mary Home, Owensboro (1938-39). She taught at St. Paul School, Leitchfield (1955-57); St. Lawrence School, St. Lawrence (1957-59); St. Mary Magdalene School, Sorgho; St. Benedict School, Wax (1960-61), and St. Joseph School, Mayfield (1972-85).
In the Archdiocese of Louisville, she served at St. Charles Convent, Lebanon (1936-38, 1951-52), St. Catherine Convent, New Haven (1939-47), and St. Columba Convent, Louisville (1950-51), and was a teacher at St. Bartholomew School, Louisville (1963-69), and St. Bernard School, Clementsville (1970-71).
In Missouri, she taught at St. Teresa School, Glennonville (1952-55) and Sacred Heart School, Poplar Bluff (1985-88). In New Mexico, she served at St. Rose Convent, Blanco (1947-50) and taught at St. Joseph School, San Fidel (1969-70). She was also a teacher at Paul, Nebraska, in 1952.
An educator for 36 years, Sister Ethelreda retired to the Motherhouse in 1988.
Survivors include two sisters, Frances Goode of Paducah and Mary Elizabeth Willett of Boaz, nieces and nephews, and the members of her religious community.
Gifts in memory of Sister Mary Ethelreda Hayden may take the form of donations to the Ursuline Sisters of Mount Saint Joseph, 8001 Cummings Road, Maple Mount, KY 42356.