<P> Mary - Kate Olsen and Ashley Olsen (born June 13, 1986), also known as the Olsen twins collectively, are American fashion designers and former child actresses . The fraternal twins made their acting debut as infants playing Michelle Tanner on the television series Full House . At the age of six, Mary - Kate and Ashley Olsen began starring together in TV, film, and video projects, which continued to their teenage years . Through their company Dualstar, the Olsens joined the ranks of the wealthiest women in the entertainment industry at a young age . </P> <P> The twins were born in Sherman Oaks, California to David "Dave" Olsen (b . 1953) and Jarnette "Jarnie" (née Jones; b . 1954). Despite being very similar in appearance, they are not identical, but sororal twins . They have an elder brother, Trent, and a younger sister, actress Elizabeth, as well as a half - sister, Courtney Taylor, and a half - brother, Jake . The twins' parents divorced in 1995; Taylor and Jake are from their father's second marriage to McKenzie . The Olsen twins have English and Norwegian ancestry . </P> <P> In 1987, at the age of six months, the twins were cast in the role of Michelle Tanner on the ABC sitcom Full House . They began filming at nine months old . In order to comply with child labor laws that set strict limits on how long a child actor may work, the sisters took turns playing the role . The Olsens continued to portray Michelle throughout the show's run, which concluded in 1995 . </P> <P> In 1992, Mary - Kate and Ashley shared the role of Michelle Tanner when they guest - starred on the Full House crossover episode of Hangin' with Mr. Cooper . While starring on Full House, the Olsens also began appearing (as separate characters) in films for video and television . The first such film, To Grandmother's House We Go, debuted in 1992 and featured cameos from several other Full House actors . In 1993, the Olsens established the company Dualstar, which would produce the twins' subsequent films and videos, including that year's Double, Double, Toil and Trouble and 1994's How the West Was Fun . A series of musical mystery videos called The Adventures of Mary - Kate & Ashley premiered in 1994 and continued through 1997 . </P>

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