Mary Kate and Ashley Olsen are one of the most fashionable twins on the planet and today, they turned 26. The fashionable duo have a very successful high end line, The Row and a contemporary line, Elizabeth and James. Its hard to tell these two apart but one tip I can give you is that Mary Kate is often wearing black. They mostly dress boho chic, often jokingly referred to as homeless chic, but also clean up nicely. They rarely wear mini dresses and never show off too much skin.