Harper began appearing in TV-movies and miniseries in the late-70s, notably in period pieces ("Little Women" NBC, 1979 and "Studs Lonigan" NBC, 1979). She continued to appear regularly in features through the early 80s in films including Allen's "Stardust Memories" (1980), as one of his neurotic objects of desire, and "Pennies From Heaven" (1981), a surreal musical set during the Depression, as the unhappy wife of a brutish Steve Martin. "My Favorite Year" (1982) would be her last major film credit for over a decade. Harper received her widest exposure as first the girlfriend and subsequently the wife of comic Garry Shandling on "It's Garry Shandling's Show" (1990). She continued to appear on TV periodically and returned to features with a small role in the underperforming Matt Dillon vehicle "Mr. Wonderful" (1993) and as Lukas Haas' mother in "Boyz" (1996).