While growing up, Warner loved to read, and her favorite book was "Alice's Adventures in Wonderland". Being in a musical family, she was predisposed to play an instrument; in her case, she chose the cello, and her father bought her a cello kit at a young age. However, because of her frequent illnesses, Warner never finished high school. After leaving in her year, she learned from a tutor and finished her secondary education. In 1918, while she was teaching Sunday School, Warner was called to teach first grade, mainly because male teachers were being called to serve in World War I. Warner continued teaching as a grade school teacher in Putnam, CT from 1918–1950. Also during this time, she returned to school for education courses at Yale University summer school.