The Scottish-born Herlie's first bout of fame in the United States occurred when she appeared as Gertrude opposite Laurence Olivier's Hamlet in the 1948 film version of Shakespeare's play; she would later play the role again on Broadway in 1964 opposite Richard Burton.

Between 1955 and 1973, Herlie appeared in nine Broadway shows, most notably The Matchmaker, in which she played Irene Molloy; Take Me Along, for which she received a Tony Award nomination for Best Actress in a Musical; Epitaph for George Dillon, All American, and Crown Matrimonial.

Her film credits also include The Story of Gilbert & Sullivan,Freud, and Sidney Lumet's film version of The Seagull, in which she played Polina. In 1976, she joined the ABC daytime drama All My Children as Myrtle Lum Fargate, a role she played until her death, and for which she received four Daytime Emmy Award nominations.