How many times do I have to say that Mulan and Pocahontas are NOT princesses? Mulan was not the emperor's daughter, and Pocahontas was simply a matriarch who was only a "princess" to the Europeans. And Nala is not even human.
Who cares what you think? If you type "list of Disney princesses" into the Google, Pochanhautus and Mulan are considered by Disney to be princesses. Official list takes precedence over some weirdo blue avatar goofball from Michigan.
What I don't get is why Kida and Elionwy are missing.
Who? Nobody knows who the hell those clowns are. If I, Vox Populi, have never heard of them, then they aren't a Disney princess. Period.