Hehe, in my theories, Vitani was the youngest and the "real chosen one", but that's just my theory. Wanted to make her story more interesting.
But of course Zira wouldn't accept that Scar's heir was a girl... Only boys can become kings.
I wonder what would've happened if Vitani really was the chosen one... SP wouldn't be any kind of a lovestory, I guess.
And if Nuka was the chosen one... oh... I'm happy that he wasn't. I mean, I feel sorry for him and all, but the movie would have been a bit different...