From 1939 to 1941 she attended Texas State College for Women and Woodbury Business College.
During the 1950s she went to work for a prominent advertising agency as a secretary. Her employer recognized her writing skills and moved her to the copywriting department where she advanced rapidly to become one of the nation's highest paid ad copywriters in the early 1960s. In 1959 she married David Brown who was a producer of Jaws, The Sting, Cocoon, Driving Miss Daisy, and other motion pictures.
In 1962 Brown authored the bestselling book Sex and the Single Girl. In 1966 she became editor-in-chief of Cosmopolitan and reversed the fortunes of the failing magazine. During the decade of the 1960s she was an outspoken advocate of women's sexual freedom and sought to provide them with role-models and a guide in her magazine. Brown claimed that women could have it all, "love, sex, and money". Due to her advocacy the liberated single woman was often referred to generically as the "Cosmo Girl". Her work played a part in what is often called the sexual revolution.
