Mary was excited to start appearing on television in its infancy. During the course of her career, she performed on more than 125 television shows.
    Her first television appearance was in 1945 on "NBC Dramatic Sustainer", a Sunday night drama. Her first live series role was "Inside U.S.A. with Chevrolet" (1949-1950), and every other week music and variety show in which she appeared in comedy skits, often as a maid or other supporting characters. In 1976, Mary said, "It has always been my ambition to be the best supporting actress in the business."
    In 1949, Mary played Mary Poppins in a live, one-hour television drama on CBS. The show was the first adaptation of the story anywhere. Mary also had many regular and recurring roles in several shows including "Halls of Ivy", "Doc", and "Father Dowling Mysteries". She also had numerous episodic appearances in shows such as "I Love Lucy", "Trapper John", "The Red Skelton Hour" and many others.