Article continues below advertisementLauren Chapin, best known for playing Kathy "Kitten" Anderson on the beloved 1950s sitcom Father Knows Best, and later advocating for the protection of child actors, has died at 80 following a five-year battle with cancer.Her son, Matthew Chapin, announced her death on Facebook. "I'm at a complete loss for words right now. Please keep my sister and family in your thoughts and prayers as we go through this incredibly tough time," he wrote.