Katharine Rayner inherited an estimated 17% stake in media and automotive conglomerate Cox Enterprises from her mother, Anne Cox Chambers. Cox Enterprises, a private company started by Rayner's grandfather, has $21 billion in revenues; it has a cable TV arm, TV stations and more. Her siblings, James Chambers and Margaretta Taylor, also inherited an estimated 17% stake each in Cox Enterprises.Neither Rayner nor her siblings or mother have ever had an active role in the company. Her cousin, Jim Kennedy, is chairman of Cox Enterprises. Rayner and her husband live in East Hampton, N.Y. She is known to be an avid gardener.