Valdis began acting in the late 1950s. She appeared in bit parts in films and guest starred in several television shows including The Wild Wild West and Kraft Television Theatre before landing the role of Hilda, Colonel Klink's secretary, in the sitcom Hogan's Heroes.
Valdis was married twice. Her first marriage was to fashion businessman George Gilbert Ateyeh, with whom she had a daughter, Melissa. Ateyeh died in 1967.
Valdis married secondly, on October 16, 1970, to Hogan's Heroes star Bob Crane on the set of the series. Following the birth of their son in 1971, Valdis retired from acting. In 1978, she moved from the Los Angeles area after Crane was murdered.
In 1980, she moved to Seattle, where in 1998 she joined the cast of her son's syndicated weekly Sketch comedy radio show, Shaken, Not Stirred. In 2004, she moved back to her childhood home in Westwood. Though no longer using her stage name, she later oversaw a tribute website to her husband, with a blog where she answered questions from fans of her husband and Hogan's Heroes.
Twice widowed, Valdis died on October 14, 2007, from lung cancer in Anaheim, California, aged 72. She was survived by her two daughters, Melissa Smith and Ana Sarmiento; son, Scott; sister Dale Gudegast and brother-in-law Eric Braeden; and one granddaughter, Robbyn Smith and four grandsons. She had three stepchildren from Crane's earlier marriage to Anne Terzian: Karen, Deborah, and Robert David Crane.