Through Western Publishing, Cobb worked as story editor (1935-1951) and later managing editor (1951-1962) for Dell, contributing to series such as Four Color, Walt Disney's Comics and Stories, Tarzan and Mickey Mouse Magazine. She was initially based in New York and moved to Western's Los Angeles office in the 1940s.

From 1962, she contributed as managing editor to Walt Disney comics for Western's Gold Key imprint.

Correspondence with Carl Barks and other comments from Western staff indicated Cobb played a strong role enforcing the style and tone of the company's comics.

Around 1968, Cobb retired from the comics industry.