Frances worked as a radio commentator in Dallas and Fort Worth. She married businessman Jacob Mossiker on October 15, 1935. The couple traveled widely and lived comfortably. They had no children. When she was in her early fifties, while recovering from a radical mastectomy, Frances Mossiker began to research the disappearance of a diamond necklace in eighteenth-century France. Through family and friends she gained access to primary documents in France, and the result was the nonfiction mystery The Queen's Necklace, published in 1961. The book won the Carr P. Collins award from the Texas Institute of Letters. Mossiker was the first woman to win the prize. She followed this book with the Literary Guild selection Napoleon and Josephine: The Biography of a Marriage (1964), The Affair of the Poisons (1969), More Than a Queen: The Story of Josephine Bonaparte (1971), Pocahontas: The Life and Legend (1976), and Madame de Sevigne: A Life and Letters (1983). She donated her papers to the Harry Ransom Humanities Research Center at the University of Texas at Austin, to Boston University, and to Smith College. She died on May 12, 1985, in Dallas and was entombed at Hillcrest Mausoleum.
32° 52.093, -096° 46.815
Sparkman-Hillcrest Memorial Park Cemetery