Mary-Kate and Ashley Olsen turn 25 years old today! The business savvy sisters made their mark as young stars in Hollywood, and now they've solidified their status as serious designers with The Row and their Elizabeth & James clothing lines. Mary-Kate and Ashley may stand out as celebrities, but sometimes it's hard to tell the almost identical twins apart. Play our fun Mary-Kate or Ashley game to see how well you know the difference between the duo on their milestone birthday!
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