Happy Birthday Princess Charlotte! Prince William and Kate Middleton's second born is now 3 years old! Look at how much she has grown since the Duke and Duchess of Cambridge first introduced her to the world outside the hospital in 2015. Charlotte, who is fourth in line to the throne, is now a middle child with the birth of the royal baby last month. InsideEdition.com's Leigh Scheps (http://twitter.com/LeighTVReporter) has more.