Tracy Nelson made a deep impression on a youthful audience in the 1980s TV series Square Pegs and is still acting today. She’s also part of show business royalty: her father was Ricky Nelson, her grandparents were Ozzie and Harriet Nelson, and her maternal grandparents were football star-turned-sportscaster Tom Harmon and leading lady Elyse Knox. (Yes, that means her cousin is Mark Harmon.) Tracy is proud of her heritage and Leonard and Jessie were only too eager to soak up all that history