Whitney died in her home in Coarsegold, California. Despite only appearing in eight episodes of the original series, Whitney officially reprised her role in Star Trek: The Motion Picture, Star Trek III: The Search for Spock, Star Trek IV: The Voyage Home, Star Trek VI: The Undiscovered Country, and Star Trek: Voyager. She also reprised the role in the unofficial Star Trek fan projects Star Trek: Of Gods and Men and Star Trek New Voyages: Phase II.
In her later years, Whitney worked as an advocate for people struggling with substance abuse. She credited her own recovery in some part to the Star Trek fans who supported her.
Outside of Star Trek, the Ann Arbor, MI. native was in the Broadway musical Top Banana, and appeared in the 1954 movie version of the show. Her TV career included roles on The Life and Legend of Wyatt Earp, The Real McCoys, The Outer Limits, Batman, and Bewitched. She also served as the inspiration for the Chicken of the Sea mermaid.