On Quincy, M.E. (1976), she played the role of Quincy's wife as two different characters.

During the 1960s and 1970s, Gillette was one of a group of mostly New York-based actors who regularly appeared in Broadway and off-Broadway productions while simultaneously appearing as regulars on such evening TV panel quiz shows as "What's My Line?", "To Tell the Truth", and "I've Got a Secret". This group of actors included Arlene Francis, Orson Bean, Kitty Carlisle, Peggy Cass, Soupy Sales, and Nipsey Russell.

Appeared in the 1998 tour of Harold Prince's "Show Boat" as Parthy. During its run at the Broward Center for the Performing Arts (Florida), Cloris Leachman had family obligations and had to leave the show for a few weeks. She played the part until Cloris Leachman returned to the show.

Co-Starring in "Zorba" at the North Show Music Theatre with Ron Holgate. (October 2001)

She and Olympia Dukakis have had the same on-screen love interest, twice: Larry Haines on Search for Tomorrow (1951) and Vincent Gardenia in Moonstruck (1987).

Appearing off-Broadway in "Flamingo Court" with Jamie Farr. (August 2008)

Was nominated for Broadway's 1978 Tony Award as Best Actress (Play) for "Chapter Two."

She is of German descent.