(written from a Production point of view)
In one of her earliest known television roles, Karen appeared with TOS co-star DeForest Kelley in a 1956 episode of Matinee Theatre. That same year, she made her film debut with an uncredited appearance in the film noir The Price of Fear with fellow TOS guest performers Phillip Pine and Warren Stevens.
Karen made an uncredited appearance in the classic Alfred Hitchcock thriller The Wrong Man, which also featured Barry Atwater, Paul Carr, Charles Cooper and Nehemiah Persoff. In 1960, she was directed by John Newland on an episode of the anthology series One Step Beyond. Karen then co-starred with Parley Baer in a 1962 episode of Wagon Train and worked with William Windom on The Farmer's Daughter in 1963.
Between 1965 and 1966, Karen played the recurring role of Mrs. Chernak on the drama series Peyton Place. Also prior to her appearance on Star Trek, Karen and her TOS co-star William Shatner appeared together in a 1966 episode of Gunsmoke (along with Liam Sullivan and Charles Seel). Her later TV credits include guest appearances on Marcus Welby, M.D., in 1972 and 1975, and an appearance on Project U.F.O. in 1978.
She was married to the actor Jeff Morrow from 1947 until his death in 1993. Karen died from complications of old age at a retirement home in Woodland Hills, California on 1 July 2009. She was 94 years old.