Born in Evanston, Illinois, she grew up in a creative environment, with her father a university professor and her mother a high school teacher. She studied at the American Conservatory Theater and Juilliard School, leading to early success with an Academy Award nomination for "Ragtime" (1981). She gained further recognition through roles in "Ordinary People" and "Once Upon a Time in America." Beyond film, she is known for her role in the TV series "Downton Abbey." She is also a musician with her band, Sadie and the Hotheads.