Kay came from an L.A. showbiz family. Her father was producer/commentator Ted Lenz and her mother model/radio engineer Kay Miller Lenz. At the ripe old age of eight weeks, Kay appeared on her first TV show produced by her dad as a baby being held up and sung to. She continued on in her father's TV shows and commercials throughout her childhood. In the 60s, she appeared as a teen on stage (Pasadena Playhouse) and in guest parts on The Monroes (1966), The Andy Griffith Show (1960) and Ironside (1967). Kay flirted with 70s film stardom after being cast by director Clint Eastwood in the film Breezy (1973) opposite William Holden as a plucky, troubled hippie/free spirit who has an affair with a much older businessman. Kay was singled out for her affecting performance but the film was ignored. She ventured on but none of her subsequent feisty roles in White Line Fever (1975), The Great Scout & Cathouse Thursday (1976), Mean Dog Blues (1978) and House (1985) put her over the top. She gained quite a bit of exposure, however, after her wedding to former teen idol David Cassidy in 1977. The marriage lasted six years. TV remained Kay's medium of choice and she has garnered two Emmy awards in the process.