(written from a Production point of view)
Sharon Thomas (born 3 June 1946; age 70) is the actress who played a bar waitress in Star Trek III: The Search for Spock. Her costume was sold off on the 40 Years of Star Trek: The Collection auction. 
Thomas is married to director Christopher Cain since 1969. The have one son, actor Dean Cain who starred along Teri Hatcher in Lois & Clark, a television series where Thomas played several minor parts and guest roles (1993-1995, with Tracy Scoggins, K Callan, Jerry Hardin, and Rob LaBelle). She has two more children from her first marriage, Krisinda and Roger Cain, both actors.
Among her acting resume are films such as Grand Jury (1976, with Bruce Davison and Eric Server), Sixth and Main (1977, with Bill Erwin), Cuba Crossing (1980), The Flamingo Kid (1984, with Brian McNamara), That Was Then... This Is Now (1985, with Barbara Babcock), Young Guns (1988, with Terry O'Quinn, Brian Keith, Geoffrey Blake and Lisa Banes), Pure Country (1992), Eating Las Vegas (1997), and Firedog (2005, with the voices of Rudolf Martin and Frank Gorshin).
Thomas' has also appeared in television series such as Barnaby Jones (1978, starring Lee Meriwether), General Hospital (1982), and The Division (2003).