Doran began acting at the age of four. According to a 1979 newspaper article, the actress made her debut at 11 years old. Rarely in a featured role, Doran appeared in more than 500 motion pictures and 1,000 episodes of television series, such as the American Civil War drama Gray Ghost.
Doran worked as a stand-in, then bit player, then incidental supporting player. By 1938, she was under contract to Columbia Pictures, where the company policy was to use the members of its stock company as often as possible. Thus, Doran appears in Columbia's serials (such as The Spider's Web and Flying G-Men), short subjects (including those of The Three Stooges, Charley Chase, Andy Clyde, Harry Langdon and Vera Vague), B features (including the Blondie, Five Little Peppers and Ellery Queen series), and major feature films. She became a favorite of Columbia director Frank Capra and appeared in many of his productions. Most of these appearances were supporting roles. In Meet John Doe (1941), she plays the wife of sodajerk-turned-John Doe Club activist Bert Hansen. Though her character speaks some of the film's most pivotal lines of dialog, including an impassioned suicide-preventing plea in the final scene, her appearance in the film is uncredited. Some of Doran's lead roles include Columbia's Charley Chase comedies from 1938 to 1940 and Rio Grande (1938) directed by Sam Nelson and featuring Charles Starrett.
Columbia filmed two boy-and-his-dog stories with juvenile star Ted Donaldson in 1945–46. When the Donaldson films became a full-fledged series (featuring the dog Rusty) in 1947, Doran was cast as Donaldson's mother in the next six films. Her steady, sensible maternal roles led to her being cast as James Dean's mother in Rebel Without a Cause (1955).
