Actress. She is best remembered for her recurring portrayal of the beleaguered Mona Kane Tyler on the soap opera "All My Children". Born Mary Heflin, she was raised in a prominent family, the second of two children born unto a dentist. After attaining her degree in theatrical arts from the American Academy of Dramatic Art in New York City, New York, she began her career on the stage appearing in "The Skin of Our Teeth." In addition, she also appeared in such productions as "All in Favor," "The Walrus and the Carpenter," "Sheppey," "I Remember Mama," "A Streetcar Named Desire," "The Tempest," "Five Evenings," and "The Physicists." Through the connections of her elder brother, the Academy Award winning actor Van Heflin, she made her film debut in "Leben des Galilei" (1947) and from there she went on to succeed as a prominent character actress in film and television; often typecast as wives, mothers, best friends, nurses, secretaries, educators, housekeepers, old maids, landladies, neighbors, snobs, debutantes, white-collared workers, and matriarchs. She appeared in such feature films as "The Molly McGuires" (1970), "The Student Teachers" (1973), and "Mr. Billion" (1977). During the advent of television, she flourished as a familiar face appearing in various guest spots on such syndicated sitcoms as "Ponds Theatre," "The Masks," "The United States Steel Hour," "Naked City," "The Defenders," and "The Patty Duke Show." During her career, she was an honorary member of Actors Equity, was a member of the Screen Actors Guild, was supportive of the Motion Picture and Television Fund, had been a lifelong member of the Actors Studio, was a theatrical instructor for the Neighborhood Playhouse, had been supportive of the New York State Democratic Committee, was a regular parishioner of the Catholic church, had been a generous benefactor for several schools and libraries, and she was married to director Sidney Kaufman from 1944 to 1946 and composer Sol Kaplan from 1947 to 1990 (her first union ended in divorce, her second upon Kaplan's death, and she mothered three children; film director Jonathan Kaplan and actresses Nora Heflin and Mady Kaplan). A lifelong smoker, she died from complications of lung cancer.