<P> Dawber screen - tested for the title role in Tabitha, a situation comedy spun off from Bewitched, which went to Lisa Hartman instead . ABC - TV, however, was favorably enough impressed with her to enroll her in its "talent development" program, which paid its participants until they could find appropriate roles . It was from this program that Garry K. Marshall recruited her . </P> <P> Dawber's professional breakthrough came when Marshall chose her, despite her having relatively little acting experience and not having auditioned for the part, as one of the two title characters of the ABC sitcom Mork & Mindy, which ran from 1978 to 1982 . She portrayed Mindy McConnell, the comedic foil and eventual love interest for the extraterrestrial Mork from the planet Ork, played by a then - unknown Robin Williams . The show was extremely popular in its debut season, when it averaged at number three in the Nielsen ratings for the year . </P> <P> Dawber sang in a 1980s Los Angeles Civic Light Opera production of Gilbert & Sullivan's The Pirates of Penzance, based on the Joseph Papp / New York Shakespeare Festival production . Her role, as Mabel, had been played by Linda Ronstadt in the New York run of the show . </P> <P> From 1986 to 1988, Dawber again had the title role in a TV series, playing Samantha Russell in the CBS sitcom My Sister Sam, co-starring Rebecca Schaeffer . The series was a success in its first season, but it suffered a massive ratings drop in its second after moving to Saturday night . My Sister Sam left the air in April 1988, with half of the second season's episodes never airing on CBS, but eventually airing (along with all previous episodes) on USA Network . In July 1989, over a year after the show's cancellation, Schaeffer was shot and killed by Robert John Bardo, an obsessed fan, in front of her apartment . Dawber reported being "devastated" by her former costar's death . Dawber and her My Sister Sam co-stars Joel Brooks, David Naughton, and Jenny O'Hara reunited to film a public service announcement about violence prevention, and Dawber herself became a gun control advocate . With the birth of her second child, she left the industry for family reasons and acted sporadically during the 1990s . </P>

Who played mindy sister on mork and mindy