Her dissertation, on algebraic curves, was supervised by Cassius Jackson Keyser; she became the fourth woman to earn a doctorate in mathematics from Columbia.
She went on leave in 1926 to assist her mother, and resigned her position at Vassar in 1929, instead becoming a high school teacher in Pittsburgh.
[1][3] She retired from teaching in 1938, had a stroke in 1941, and died on April 13, 1945, in Fort Lauderdale, Florida.
[3] Cowley and her co-author Ida Whiteside won a prize for a 1907 paper they wrote on the orbit of comet C/1825 V1.
She was an invited speaker at the International Congress of Mathematicians in 1932, speaking there about mathematics education.