Cooley taught at Hampton Institute as a young woman. She taught at the Penn School on Saint Helena Island beginning in 1901, and became the school's principal in 1908, succeeding
Laura Matilda Towne. She reorganized the school's curriculum along the lines of Hampton Institute's, to emphasize practical skills including carpentry and nursing. Much of her work involved promotion and fundraising. She wrote two books about the school, and several articles. Her sister Mabel organized a Penn School Club at Vassar, to collect donations from the student body for Cooley's work.
Ella McCaleb was president of the Penn School Club at Vassar in 1932. Cooley was retired from her position in 1944, by the school's trustees. The school closed in 1948. ==Publications==