Mary-Kate Olsen

American fashion designer, former actress and producer. She and her fraternal twin Ashley have starred in many TV programs and movies beginning at an early age. When the twins were four months old, a close family friend persuaded their mother to take the babies to an audition for a TV sitcom. Reportedly they were the only babies who didn't cry during the audition and they landed the part of Michelle Tanner on a new hit series, "Full House." At nine months of age, they shared that role from the show's debut in 1987 until its cancellation eight seasons later in 1995. During that time, the twins were such a hit that books, dolls and other merchandise bearing their name proliferated. They twins, with their parents' guidance, formed a company when they were six, Dualstar Entertainment, specifically to handle the business side of their fame, which has grown to include videos and movies, books, clothing and fashion accessories.

In 1995, at age nine, the twins made their first feature film, "It Takes Two," for which they were paid $1.6 million. In 2001, Dualstar Entertainment earned $500 million and in 2002 around $1 billion. Although their parents divorced in 1993, and their father remarried, both parents remained close to their girls, making sure that they remained level-headed about their fame and finances. In 2004, as teenagers, the twins released a major motion picture called "New York Minute." That same year, the teen moguls were accepted to the class of 2008 at New York University's Gallatin Program for Individualized study. On 22 June 2004 news broke that a week or two prior, Mary-Kate had entered a clinic for treatment of an eating disorder that she had been battling for some time. Her twin Ashley cancelled their tour to Australia and New Zealand to be with her sister.

Although the twins look alike and are quite close, they have different personalities and interests.