In 1938, at age 16, she starred in the cliffhangers: The Lone Ranger and Dick Tracy Returns, and played a role in The Higgins Family.

[citation needed] In 1941 she starred with Sonja Henie and John Payne in Sun Valley Serenade, while under contract to 20th Century-Fox.

(Johnny D. Boggs, in his book, Billy the Kid on Film, 1911-2012, wrote, "Lynne Roberts would co-star with [Roy] Rogers in eight Westerns, billed as Mary Hart in the first seven of those.

[7] In 1953, Roberts married brassiere manufacturer Hyman B. Samuels, with whom she had a daughter, Peri Margaret, and a son, William Edward.

[9] Roberts retired from acting and later married pro wrestler and motion picture actor Don Sebastian in 1971, but she was separated from him at the time of her death.