Mitchell, who was thought to be the last living adult cast member from Lucille Ball's iconic CBS sitcom, died on Monday (Nov. 11) of heart failure in her Westwood condo, her sister-in-law, "Sunset Blvd." actress Nancy Olson, tells THR.
Mitchell joined the cast of "I Love Lucy" for the 1953-54 season, appearing in three episodes. Marion, known for her cackling laugh, faces frank opinions in one episode, "Lucy Tells the Truth."
"Marion, stop cackling," Lucy tells her. "I've been waiting 10 years for you to lay that egg!"
The character, which was originally played by Margie Liszt in the show's second season, set Lucy and Ricky up on their first date.
Born in 1919, Mitchell began her career as a radio star, becoming good friends with