We love the Duchess of Cambridge for her contagious smile, accessible style, and ability to let loose . But let's be real: she's a princess . Since Kate's so seemingly effortless, it's easy to forget that her royal highness has to follow royal protocol and make polite conversation with world dignitaries on a regular basis. She is pregnant, raising the future king of England, and married to another one, after all. To prove Kate, who turns 33 on Friday, is living up to her role, here are her most royal moments.