Two members of the Walton family, owners of the Walmart retail chain, are among the world's five top female billionaires, according to Wealth-X, a global ultra-high-net-worth prospecting and research firm based in Singapore.

Alice Walton came in first with $29.8 billion due to Walmart stock trading at a 12-year high. Wealth-X says there are 3,000 female billionaires worldwide.

She pushed out Gina Rinehart, an Australian mining magnate, who was first last year and second this year with a net worth of $29.1 billion.

The second Walton on the top five list, Christy Walton, is third with $28.2 billion. The woman behind L'Oreal, Liliane Bettencourt of France, placed fourth with $24 billion. Fifth on the list is Birgit Rausing, Swedish-born and Swiss-based, who has $13.8 billion largely from shares in Tetra Laval, the packaging firm.

-Karen DeMasters