Mary Eleanor Donahue (born April 19, 1937), credited as Elinor Donahue, is an American actress, best remembered today for playing the role of Betty Anderson, the eldest child of Robert Young and Jane Wyatt, on the 1950s American sitcom Father Knows Best. Donahue achieved stardom for her role as the elder daughter, Betty, on the television family series Father Knows Best. Her co-stars were Robert Young, Jane Wyatt, Billy Gray as her younger brother, James "Bud" Anderson, Jr., and Lauren Chapin a...