Innes spent much of the 1980s honing her talents onstage, including a four year stint acting with Chicago's Goodman Theater, where she appeared (as Stella) alongside John Malkovich (as Mitch) in a Chicago production of "A Streetcar Named Desire" and in the premiere of David Mamet's "Edmund". Her other stage work has included the Broadway production of "Two Shakespearean Actors", "Our Town" (Seattle, WA) and "Three Sisters" (La Jolla, CA). She also had a supporting role in the pilot "The Stiller and Meara Show" (NBC, 1986) and the TV-movies "Jacob Have I Loved" (PBS, 1989) and "Philby" (ABC, 1989).

After her marriage and the birth of her son, Innes decided to move to L.A. to pursue a career in TV and films. She guested on such shows as "My So-Called Life" and "Brooklyn Bridge" and from 1991-1993 appeared in several episodes of "Wings" (NBC) as Bunny, the dizzily nymphomaniac ex-wife of eccentric mechanic Lowell Mather (Thomas Haden Church). Innes also had small roles in four 1993 TV-movies, notably "Judith Krantz's 'Torch Song'" (ABC) and the award-winning "And the Band Played On" (HBO), as an hemophiliac.

In 1995, she simultaneously played two roles: Louie Anderson's wife on the short-lived CBS sitcom "The Louie Show" (which was broadcast early in 1996), and the stern Dr. Weaver on 14 episodes of "ER". In 1996, she had a leading role in the Disney TV-movie "Just Like Dad" and her popularity was rewarded when Dr. Weaver was made a permanent cast member of "ER" as of the 1996-1997 season. The character's hard edges were also softened a bit to make her more palatable for the long haul.