I was a Mulan girl. Back when I was a little girl, Mulan was one of an array of Disney princesses adored by little girls everywhere. Among the more popular choices were the traditional, delicate, and iconic ones. There were also the more unconventional princesses—those who gave off an air of rebellion, yet were still, in their own ways, glamorous and admirable. But I felt the most connected with Mulan, the only Disney princess who was a princess in...