49. SARAH MacMILLAN
THE MONEY: MacMillan is a great-great-granddaughter of W.W. Cargill, who started the Cargill Inc. empire, one of the largest grain commodity traders in the world, by opening a small grain storage business in Conover, Iowa, in 1865. The company is the largest privately owned business in the United States. It has 150,000 employees and operates in 70 countries.
THE BUZZ: When her father, W. Duncan MacMillan, died in 2006, media reports estimated that MacMillan and her three sisters each received a 3 percent stake in the company. MacMillan keeps a very low profile and is rarely seen in public. She lives in Malibu and was once married to Blaine John Chaney, guitarist from 1980s Minneapolis rock band the Suburbs.
NET WORTH: $1.35 billion
LAST YEAR: Not on list
AGE: 28
RESIDENCE: Malibu
SOURCE OF WEALTH: Agribusiness