A longtime member of Chicago's Steppenwolf Theatre Company, she has appeared in more than 50 productions at that theater.

Also active on Broadway, she won the 2008 Tony Award for Best Performance by a Featured Actress in a Play for her portrayal of Mattie Fae Aiken in August: Osage County.

She then met a Broadway theatrical producer named Stephen Eich in 1976 during her time in Steppenwolf Theater and married him in 1982.

She originated the role of Mattie Fae Aiken in the Broadway production of August: Osage County in 2007, for which she won the 2008 Tony Award for Best Performance by a Featured Actress in a Play.

She began performances March 17, 2009,[4] replacing Jayne Houdyshell and bowed out as the evil headmistress on June 27, 2010, to star in the Australian production of August in Sydney.