Known as "Mother of Women's Swimming in America," Epstein founded the Women's Swimming Association and coached the Women's Olympic Swimming Team in the 1920s. Epstein was born in New York City where she became a court stenographer. In 1917, after she and a few other businesswomen expressed their desire to swim after work for exercise, Epstein formed the Women's Swimming Association to promote the health benefits of the sport. As manager and president of the WSA, Epstein guided many of its members to Olympic victory; she herself was the U.S. Women's Olympic Swimming Team's manager for the 1920, 1924, and 1928 games. Swimmers under her leadership won thirty national championships and set fifty-one world records. In 1935, Epstein chaired the swimming committee in charge of team selection at the second Maccabiah Games in Tel Aviv; the next year, she boycotted the Olympics in Berlin in protest over Nazi policies.