This month the daughter of Edward "Ned" Johnson III, lord of the world's largest mutual fund company, took charge of the board governing the company's fixed-income and asset-allocation funds. She now oversees 161 funds with more than $650 billion in assets.
Many Fidelity watchers believed "Abby" fell out of contention for the top spot at the company after her father moved her from the venerable mutual fund division to the more mundane retirement and retail group in 2005. (Others saw that move as an opportunity for her to understand another part of the family business.) Johnson will continue to run the retail group--the firm's largest division with $1.3 trillion in customer assets--as she takes on her new responsibilities.
A spokesman for Fidelity would not comment on the company's succession plans. He said the move was the logical next step in its strategy to split its board of trustees in half, and Ned Johnson has no plans of retiring.
Like the majority of the female billionaires in the world, Johnson inherited her fortune--yet still holds tremendous sway over her company. Today she's worth an estimated $8.5 billion, ranking her eighth on the new Forbes list of the world's richest women.
Topping the list is Christy Walton, who is worth $20 billion. Walton is the widow of Wal-Mart ( WMT - news - people ) scion John Walton, who died in a plane crash in 2005. Right behind her is Alice Walton, worth $19.5 billion.
Alice is the daughter of Sam Walton, who with his brother James, started a general store chain in Bentonville, Ark., in 1962. Today Wal-Mart is the world's largest retailer, controlling more than 7,900 stores, 2 million employees and $400 billion in annual sales.
This year the 20 richest women on the planet have a combined net worth of $160 billion derived from a diverse string of industries including manufacturing, finance, real estate and commodities.
While nearly all of their personal balance sheets took a hit in the past 12 months, most of the world's richest women have rehabbed their riches since the global equity markets bottomed out. Since we published our list of the World's Billionaires in March, this elite group has added $20 billion in cumulative wealth.
Behind the Waltons is L'Oreal heiress Liliane Bettencourt, who is worth $15 billion and has endured a scandalous year. Her daughter, Francoise Bettencourt-Meyers, filed a criminal complaint after the make-up matriarch reportedly gave $1.3 billion in assets and life insurance benefits to photographer Francoise-Marie Banier (See "Une Affaire de Famille"). Bernard Madoff's investment fraud also reportedly devoured some of her family's funds (See "L'Oreal Family Mixed In With Madoff").
The world's fourth richest woman, Susanne Klatten (worth $12 billion), has also been mired in scandal recently. Last January she was forced to go to the police after a former lover, Helg Sgarbi, allegedly threatened to post videos of the two having sex on the Internet (See "Billionaire Sex Scandals"). Sgarbi had secretly videotaped the two in hotel rooms on several occasions and demanded millions of Euros in hush money. In March Sgarbi was sentenced to serve six years in prison for the attempted blackmail.
Female billionaires who didn't make the top 20 include Harry Potter author J.K. Rowling, former eBay ( EBAY - news - people ) chief Margaret Whitman and media maven Oprah Winfrey. Oprah, worth $2.7 billion, recently slipped to No. 2 on the most recent Forbes Celebrity 100 ranking of the world's ultra famous.