A self-described "Navy brat," then a "defense corporation brat," Richardson was born in Bethesda, Maryland, and moved with her family frequently during her childhood. Making new friends in every town forced the young girl to be outgoing, and sparked her early interest in a career as an actress.

After an unlikely stage debut as a male cop in an all-girl school play, Richardson started seriously pursuing her craft. Following her graduation from Southern Methodist University, she moved to New York, where her first audition won her the role of understudy for young Gypsy Rose Lee in the Angela Lansbury revival of "Gypsy." She ended up working with the company on Broadway and on tour for 11 months in a variety of roles. Additional Broadway credits include "Loose Ends" and "The Wake of Jamey Foster."

Off Broadway, Richardson appeared in productions of "Vanities," "Hooters," and "The Miss Firecracker Contest," which was written by her former classmate, noted playwright Beth Henley. Her performance in "Cruise Control" was heralded by "New York Magazine" as "one of the ten best of 1985." Her work in the play also earned her a 'Hirschfeld' in the "New York Times," a sure signal to the New York theater community that she had arrived.

In 1988, Richardson relocated to Los Angeles to pursue television acting full-time. She quickly landed regular roles in "FM," "Eisenhower and Lutz," and "Double Trouble," before winning the role of Jill Taylor on "Home Improvement."

In 1998, Richardson received an Independent Spirit Award nomination for her starring role opposite Peter Fonda in "Ulee's Gold." In this, her first starring role in a motion picture, she portrays Connie, a nurse whose compassion helps both Ulee (Fonda) and herself overcome ghosts of the past.

Richardson has also applied her talents to film roles in "Lost Angels," with Donald Sutherland, and "In Country," with Bruce Willis. Her other television credits include her telefilm debut in Lifetime's "Sophie and the Moonhanger," for which she received critical acclaim playing the abused wife of a Ku Klux Klan official, and the miniseries "Undue Influence," based on Steve Martini's "New York Times" best-seller, in which she starred opposite Brian Dennehy.