[2] Her early years were spent living in the care of her mother, Joan Ida Headly (née Sniscak),[3] in San Francisco, and her maternal grandmother in Lansford, Pennsylvania.

There, a fifth-grade teacher introduced her to the work of Jacques Cousteau in an oceanography class, triggering a lifelong interest in preserving the natural world.

She was eventually cast in a Goodman Theatre production of Curse of the Starving Class, directed by Robert Falls and co-starring John Malkovich.

She received her Actors' Equity card when cast by Vivian Matalon in a summer theatre production of Charley's Aunt, and joined SAG when Arthur Penn wrote a breakout role for her in the film Four Friends.

[4] In New York, she appeared in Balm in Gilead with her fellow Steppenwolf Theatre members,[9] and in Arms and the Man, on Broadway, with Kevin Kline and Raul Julia.

Right, Paperhouse, Seize the Day and Nadine, but her role in Dirty Rotten Scoundrels (1988), with Steve Martin and Michael Caine, truly launched her film career.

[12][13][14] In 1989, Headly played the role of Elmira Boot Johnson in the critically acclaimed TV miniseries Lonesome Dove, a part for which she received her first of two Emmy Awards nominations for best supporting actress in a television movie.

Encore!, starring Nathan Lane and Joan Plowright, from 1998 to 1999,[20] and had recurring roles as Dr. Abby Keaton on ER from 1996 to 1997[21] and as Leland Stottlemeyer's wife, Karen, on Monk.

Headly and Ed Begley Jr. were cast in lead roles with Josh Hutcherson in Future Man, Hulu's half-hour comedy television series produced by Seth Rogen and Evan Goldberg.

[28][29] Headly was an ensemble member of the Steppenwolf Theatre Company from 1979 until 2005,[30] although she never returned to Chicago to do a play after the late 1980s, believing that such a move would uproot and be disruptive to her family.

She took a break from the stage altogether for 10 years until 1999, when she starred with Miranda Richardson in Wallace Shawn's Aunt Dan and Lemon, which premiered at the Almeida Theatre in London.

[34] In 1984, Headly appeared in Lanford Wilson's Balm in Gilead presented by the Circle Repertory Company and the Steppenwolf Theater Ensemble.