She became a member of the New York Municipal Opera Company on a scholarship and sang the lead at Carnegie Hall in such presentations as La bohème, Traviata, and Pagliacci.

Her appearance in that revue led to her being cast in her first movie role, in I Married an Angel (1942), starring Nelson Eddy and Jeanette MacDonald.

She was under contract to both RKO and Republic Studios during the 1940s, including several appearances as Tess Trueheart in the Dick Tracy series, and the 1944 Frank Sinatra musical Step Lively.

She also appeared in the horror comedy Zombies on Broadway with Wally Brown and Alan Carney in 1945 and starred in Riffraff with Pat O'Brien two years later.

On December 18, 1957, Jeffreys and her husband played a couple with an unusual courtship arrangement brought about by an attack of the fever in the episode "The Julie Gage Story", broadcast in the first season of NBC's Wagon Train.

[3] She also appeared in Baywatch as David Hasselhoff's mother, and also had a recurring role in the night-time soap Falcon Crest as Amanda Croft.

[citation needed] In 1979, she guest starred as Siress Blassie in the Battlestar Galactica episode "The Man with Nine Lives" as a love interest of Chameleon, a part played by Fred Astaire.

In her initial storyline, she was part of a blackmail scheme which led to the murder of Jimmy Lee Holt's mother, Beatrice, of whose death she was a suspect in.

Sterling appeared with Jeffreys in one episode of the series Wagon Train ("The Julie Gage Story", in which their characters also married each other), and in Topper.