A native of Rockville, Maryland, Marshall's big break came when she landed a guest-starring role on Seinfeld. Marshall earned a commitment from NBC to develop a series to showcase her comedic talents after her memorable performance as the young college reporter who overhears a conversation between Jerry and George that leads her to think they are gay in the famous episode, The Outing.

In her career, Marshall has earned an impressive list of television credits, including a six-episode run on Spin City as Michael J. Fox's fianc饮 Her additional television credits include series regular roles on David E. Kelley's Snoops, Cupid, and Chicago Sons and a recurring role opposite Steven Weber on The Weber Show, and recurring roles on Life Goes On, The Wonder Years, Sports Night, and Veronica Mars.

Marshall has also made her mark on the big screen, starring as Bette Midler's daughter in the romantic comedy, That Old Feeling; as Robert Duvall's daughter in A Family Thing; and appearing in the feature film The New Age, with Judy Davis and Peter Weller.