Millicent Cook Daly, 57, who retired in 1977 after 33 years as a D.C. public school teacher, died of cancer Friday at the Mar-Salle Convalescent Center here.

Miss Daly, a Washington native, was born into a family of Washington educators. Her earliest ancestor here was Thomas Cook, who settled here in 1806 and operated a vegetable garden, known as Cook's Farm, site of the present day corner of 16th and K Streets NW.

Her great-great-grandfather, John F. Cook, was a militant Washington educator. His son, George F. T. Cook, a school superintendent, directed the public education of "children of freed colored people" at the Sumner School here from 1869 until 1900.

For 29 years, until Sumner's closing in 1972, Miss Daly taught first-grade in the same room that her great-grandfather had used as his office. f

After the school's closing, she taught at the Ross School in Washington.

A graduate of Dunbar High School, where her mother, the late Adelaide Cook Daly, taught Spanish for 30 years, Miss Daly earned a bachelor's degree from the old Miner Teachers College and a master's degree in education from New York University.

Survivors include her father, Victor Daly, a retired deputy director of the U.S. Employment Service, and herstepmother, Lenore B. Daly, both of Washington, and a sister, Peggy D. Waters of San Jose, Calif.