Edith Vernick
Edith Vernick was an American animator, hired by the Fleischer Studios in the mid-1920s and became the In between Department Supervisor. Her animation work is uncredited on The Fresh Vegetable Mystery from 1939. Although Lillian Friedman Astor is generally considered the first female American animator, Vernick’s employment at the Fleischer Studios preceded Friedman’s.
https://en.wikipedia.org/wiki/Edith_Vernick