Mary-Kate and Ashley Olsen

At 18, Mary-Kate and Ashley Olsen aren’t just rich and ambitious, they are mini-moguls. They are already worth $40 million and counting.

Born in Sherman Oaks to David Olsen and Jarnette Fuller, Mary-Kate and Ashley Fuller Olsen also have an older brother, Trent, and younger sister, Elizabeth, as well as two half-siblings, Taylor and Jake. The twins' parents divorced in 1995, and Taylor and Jake are the children from their father's second marriage.

Not quite identical twins but close enough to act the same part on TV, Mary-Kate and Ashley began splitting a role on the popular sitcom, Full House, literally before they could walk. By the age of four they were child stars, the lynch-pin of the show and earning a pittance.

When he saw how little the girls were paid, Robert Thorne, a producer, asked the twins’ parents if he could represent them. He secured a raise of $150,000 each per episode. “Full House” was cancelled in 1995 and Thorne took a chance and cast the twins in their own adventure videos.

The films, full of clean fun, immediately appealed to the ‘tweenies’, kids who have grown out of cartoons and are not yet into teen movies. Thorne founded a company called Dualstar and made the seven year old girls executive producers. Together the trio hired directors, writers and oversaw the entire presentation of the Dualstar brand.

As the sisters grew older and more mature in their style, there was a greater interest in their fashion choices. The New York Times declared Mary-Kate a fashion icon for pioneering her signature "Boho-chic" look, consisting of oversized sunglasses, boots, loose sweaters, and flowing skirts.

Mary-Kate and Ashley have a clothing line in Wal-Mart stores across America for girls ages 4-14, as well as a beauty line called "Mary-Kate and Ashley: Real fashion for real girls". They have also been working on a new couture label 'The Row' named after the famous Savile Row of London.

In 2004, Mary-Kate checked into rehab for six weeks because she was suffering from an eating disorder. It was rumoured that there was also a drug problem, but the Olsens' publicist denied this. Mary-Kate put on about five to seven pounds immediately after her stint in rehab.

The following year, Mary-Kate ended her romance with Greek shipping heir Stavros Niarchos III, who later began dating hotel heiress and socialite Paris Hilton. She is now engaged to Olivier Sarkozy, the half brother of the former French President Nicolas Sarkozy.