The first involved her dancing skills in a TV commercial. Her perky character was "Happy Hotpoint."
1956: Hotpoint Refrigerators and Dishwashers. This was a lead-in to the sitcom The Adventures of Ozzie and Harriet. Hotpoint, like Kodak cameras, was a long-term sponsor of the show.
1959: As "Sam" on Richard Diamond, Private Detective. This TV adaptation of the long-running radio series (starring Dick Powell), a sort of Film Noir lite, gave David Janssen his first TV platform before he became a pop culture icon as The Fugitive. Re-runs were titled "Call 'Mr. D.'" Mary, always in the shadows, played "Sam," who worked for Diamond's answering service. Only her legs were on camera; otherwise, she was seen only in silhouette. She recalls doing just 12 episodes in Season 3.
She shows up at 1:57, right after the opening.
And at 14:32
1986: Mary on The Richard Diamond phase, interviewed for the Archive of American Television (connected to the Emmys). She discusses the dozen episodes she did, why she left, and the benefits.