Wendy Moira Angela Darling is a fictional character and one of the main protagonists of the 1904 play and 1911 novel Peter and Wendy by J. M. Barrie, as well as in most adaptations in other media. Her exact age is not specified in the original play or novel by Barrie, though it is implied that she is about Peter's age as she is "just Peter's size".
As a girl on the verge of adulthood, she stands in contrast to Peter Pan, a boy who refuses to grow up, the major theme of the Peter Pan stories. Wendy hesitates at first to fly off to Neverland, but she comes to enjoy her adventures. Ultimately, she chooses to go back to her parents and accepts that she has to grow up.
Source : Wikipedia