[1][3] She had one sister, Rose, who died at age 27,[4] and one brother, Jack, who became a professor of modern languages and linguistics at the University of Texas at El Paso.

Her articles covered topics such as a woman who claimed to have "prayed herself thin", the keeper of the Great Seal of the United States, and a student at Georgetown University who had been a freshman for twelve years.

[7] The first book she ghostwrote was published in 1957, after The American Weekly gave her an assignment to write a profile of François Rsavy, Dwight D. Eisenhower's chef.

Leighton came up with White House Chef which was described as "chatty and surprisingly candid" and selected for preservation in an underground vault by the Library of Congress.

[8] In a profile published that year, The New York Times described her as "one of those people one occasionally meets whose unflagging energy and overwhelming bounce make you feel desperately in need of a nap."

[7] In 1976, she began working to ghostwrite a book by William Miller about his time as Doorkeeper of the United States House of Representatives.

[2][14] Her will established a trust to divide money between the town of Thompson and the Ledgemont School District to improve the local library.

[2][8][16] After the book's publication, First Lady of the United States Jacqueline Kennedy had her staff sign an agreement to not publish memoirs.

[13] The book was very successful, spending 36 weeks on The New York Times Best Seller list, selling over 600,000 copies and spawning a 1979 NBC mini-series, Backstairs at the White House.

The two spent around six months revising the manuscript into a 396-page book that was published as My Life with Jacqueline Kennedy in 1969 to generally negative reviews.

[2][19] The New York Times called the book "a worm's-eye view of history commercially packaged by a backstairs ghost" and noted that Gallagher provided "the venom" and "details" to Leighton, who "blended them together with the precision of a hack.