Roberts began publishing in 1942, when she released More Than You Promise, a joint effort with author Kathleen Smallzried detailing the history of the Studebaker Corporation. Roberts then moved into fiction, publishing her first novel, A Man of Malice Landing, in 1943. By 1964, Roberts had produced fourteen published novels (with one, If a Body Kill a Body, under pseudonym Peter Mortimer). A number of these were based on Arthurian legends, although Roberts also wrote Irish and Icelandic historical fiction, as well as producing contemporary American fiction.
Roberts died in February 1990.