Reed has been a member of Chicago's Steppenwolf Theatre Company for many years, appearing in 51 productions with the company.
She appeared on Broadway in The Rise and Fall of Little Voice in 1994 and The Grapes of Wrath in 1990, among others.
On July 13, 2005, she originated the role of Madame Morrible in the Chicago production of the musical Wicked.
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 later reprised her role of Madame Morrible in Wicked in Chicago, beginning June 27, 2008.
Her second run ended November 18, 2008 and she was again replaced by Robertson.
She then reprised her role as Mattie Fae Aiken in the London production of August: Osage Country before returning to Madame Morrible in the Broadway production of Wicked.
She began performances March 17, 2009, replacing Jayne Houdyshell and bowed out as the evil headmistress on June 27, 2010, to star in the Australian production of August in Sydney.
The limited engagement of the show ran from August 13-September 25, 2010.
She returned to the New York production of "Wicked" from July 31, 2017 to January 28, 2018.
She appeared in the Seinfeld episode "The Kiss Hello" (originally aired on February 16, 1995).
She starred on the CBS sitcom Mike & Molly, as Peggy Biggs, Mike's mother.
She also appeared on Roseanne as Jackie's therapist.
When astronaut Spencer Armacost returns to Earth after a mission that nearly cost him his life, he decides to take a desk job in order to see his beautiful wife, Jillian, more often. Gradually, Jillian notices that Spencer's personality seems to have changed, but her concerns fade when she discovers that she's pregnant. As Jillian grows closer to becoming a mother, her suspicions about Spencer return. Why does it seem as if he's a different person?
Uptight New York City executive, Michael Cromwell, pursues his soon-to-be ex-wife to South America and returns home with the son he never knew he had—a boy raised in a tribal village in Brazil. Armed with only his blowgun, the 13-year-old Mimi-Siku discovers that the world outside his jungle home is indeed a strange place.
After a terrible air disaster, survivor Max Klein emerges a changed person. Unable to connect to his former life or to wife Laura, he feels godlike and invulnerable. When psychologist Bill Perlman is unable to help Max, he has Max meet another survivor, Carla Rodrigo, who is wracked with grief and guilt since her baby died in the crash which she and Max survived.
A rich millionaire hires a sophisticated journalist to bring his somewhat dim-witted girlfriend up to the level of his peers. He fears that the showgirl's lack of etiquette may damage his own social reputation and tries to change her — but fails to realise that her enhanced eloquence will empower her to voice her own strong opinions.
Trying to get his act together, a con artist gets a job in a credit card company. He falls in love with a fellow employee, he steals a couple of cards, everything is going great. But soon, the chief of security drags him into the big leagues of criminals...