It's one thing to live for years undetected with a fortune of $12.7 billion. It's another to do it as the 77-year old daughter-in-law of the late, pneumatic, reality-TV phenomenon Anna Nicole Smith.
As to how a 77-year-old could be the "daughter" of someone who, if she were alive today, would be 44, is a question we'll get to in a minute.
As for how the 4th richest woman in the United States—whose $12.7 billion puts her behind only three other women--could have escaped detection until now by billionaire-hunters, Peter Newcomb, editor in charge of the Americas for Bloomberg News's Billionaire Index, has an explanation.
"She's extremely low-key," he says.
Elaine Tettemer Marshall is not the kind of woman given to dancing on tables, buying Hawaiian islands or throwing her underwear out of cars. Both before and after the 2006 death of her husband, E. Pierce Marshall, she apparently has led a circumspect and quiet life.
Newcomb tells ABC News he and his Bloomberg colleague Matthew Miller stumbled on her fortune only after they got to wondering one day who owned the minority stake in Wichita's Koch Industries, second-largest closely-held company in the U.S.
The majority owners are the Koch brothers, Charles and David, famous (or infamous, depending on your politics) for bankrolling conservative causes. Though the brothers own most of the fabulously profitable company (whose sales Bloomberg puts at $110 billion a year), they do not own it all. Some 15 percent belonged to E. Pierce Marshall. And this share, after his death, passed to Elaine.
Her estimated worth of $12.7 billion, says Newcomb, puts Elaine behind two Wall Mart heiresses, Alice and Christy Walton; and candy company beneficiary Jacqueline Mars.
Bloomberg says that the ability of Elaine and Piece Marshall to avoid publicity contrasted sharply with the ability of Pierce's father, J. Howard Marshall, to attract it. He never did that better than in 1994, when, at the age of 89, he wed former stripper and Playboy model Anna Nicole Smith, 26, at the time. As J. Howard's wife, she became Elaine's mother-in-law.
Years of legal wrangling between Smith and the Marshall family followed J. Howard's death in 1995, the upshot of which was that Smith never inherited a cent of the family fortune, says Bloomberg.
A representative for Elaine Marshall declined to comment on Bloomberg's revelation of her wealth, beyond saying that Mrs. Marshall does not own any Koch stock in her own name.
Bloomberg started its Billionaire Index in March with a ranking of 20 wealthy individuals. Updated daily, it since has grown to include 100. Make that 100-and-one.