Peggy Knudsen portrayed Mrs. Mona Mars in the 1946 Humphrey Bogart classic THE BIG SLEEP (1946), the wife of Mr. Big, as it were, around whom much of the plot turned. The role was played by one Patricia Clarke in an early version of the film that was shelved after Warner Bros. demanded additional scenes to be filmed with the red-hot Lauren Bacall. Exit Miss Clarke, who did not quite live up the all the exposition, and enter Miss Knudsen, who did. It was one scene only but both critics and the audience at large took notice. Unfortunately, the powers at be at Warner Bros. paid little or no attention and Knudsen's follow-ups were forgettable. Twice divorced and the mother of three children, Knudsen would later suffer from a debilitating arthritic condition, her medical bills paid for by her best friend, movie star Loretta Young, with whom she had stayed while making her initial screen test for Warners back in 1945. Knudsen was awarded a star on the Hollywood Walk of Fame in 1960, an honor that probably came courtesy of Miss Young. She died in Encino aged 57 in 1980.
The final film of Peggy Knudsen:
ISTANBUL (Universal-International, 1957) D: Joseph Pevney. CAST: Errol Flynn, Cornell Borchers, John Bentley, Torin Thatcher, Leif Erickson, Peggy Knudsen (Marge Boyle), Nat "King" Cole. The life and times of a dashing diamond smuggler and his glamorous paramour (German star Borchers) who may or may not be what she appears. Knudsen and Erickson play typical "ugly Americans" who also may be something other than what they appear to be. Flynn had replaced Jeff Chandler in this remake of the 1947 melodrama SINGAPORE. Knudsen later did her fair share of television guest roles and had a recurrent role on the sitcom "The Adventures of Ozzie and Harriet. "