Following her resignation from Viking Press, Onassis was hired by Doubleday, where she worked as an associate Editor under an old friend, John Turner Sargent, Sr. Among the books she edited for the company are Larry Gonick's The Cartoon History of the Universe, the English translation of the three volumes of Naghib Mahfuz's Cairo Trilogy (with Martha Levin), and autobiographies of ballerina Gelsey Kirkland, singer-songwriter Carly Simon, and fashion icon Diana Vreeland. She also encouraged Dorothy West, her neighbor on Martha's Vineyard and the last surviving member of the Harlem Renaissance, to complete the novel The Wedding (1995), a multi-generational story about race, class, wealth, and power in the U.S..