(written from a Production point of view)
Washburn was born in Los Angeles, California. As a child actress, Washburn made her Hollywood debut with an uncredited appearance in the 1950 film The Killer That Stalked New York. Fellow TOS guest stars Whit Bissell and Celia Lovsky also appeared in this film-noir about a carrier of the deadly smallpox disease. Washburn was next seen in Frank Capra's classic Here Comes the Groom in 1951, a musical comedy also featuring TOS alum Ian Wolfe. That same year, she appeared in Superman and the Mole-Man, a classic science fiction feature co-starring two more TOS guest performers, Stanley Adams and Jeff Corey.
She appeared in many other films throughout the 1950s, including Cecil B. DeMille's The Greatest Show on Earth (1952, with Lawrence Tierney), Shane (1953, with Elisha Cook, Jr.), and The Lone Ranger (1956, with Michael Ansara and William Schallert). Also during this time, she apeared on such television shows as The Jack Benny Program, Dragnet, Fireside Theatre, Studio 57, Four Star Playhouse, Letter to Loretta, General Electric Theater, Wagon Train, One Step Beyond, and Leave It to Beaver. Perhaps her most significant role, however, was that of Lisbeth Searcy in the the classic 1957 family drama Old Yeller.
During the early-to-mid 60s, Washburn focused entirely on television, including appearances on Thriller, Wagon Train, 77 Sunset Strip, The Patty Duke Show, and Gidget. It wasn't until the late 60s that she returned to films, appearing in Spider Baby, or The Maddest Story Ever Told (1968) and The Winner (1969), both featuring fellow TOS guest star Sid Haig.
Her career slowed down significantly during the 1970s. During this time, she appeared in three episodes of The Streets of San Francisco (starring Darleen Carr. One of these episodes, 1975's "Letters from the Grave", also featured William Windom. As slow as her career was in the 70s, it only got more so in the 80s and 90s: her only known credits during these decades were a guest spot in a 1984 episode of Scarecrow and Mrs. King, with Henry Darrow and Keone Young, and an uncredited appearance in the 1994 TV movie Children of the Dark, with fellow Star Trek alumni Jim Beaver, David Graf, Lenore Kasdorf, Thomas Kopache, Glenn Morshower, Natalia Nogulich, Eric Pierpoint, and Bill Smitrovich. She also appeared in featured roles in Murder She Wrote and for four years on General Hospital.
She recently returned to Hollywood, appearing in the 2003 pilot episode of the television series Las Vegas, starring Nikki Cox. She can also be seen in the 2005 comedy Hard Four opposite Ian Abercrombie, Ed Begley, Jr., Hamilton Camp, and Michele Scarabelli.
Washburn currently resides in Las Vegas.