If Twilight never became a princess, then how was Sunset reformed?
Seeing as how the human world is Equestria's garbage dump, that isn't a big problem. There is another "good" Equestrian in the human world, and her name is Evening Star.
This story is a side story to my story Lovely Chaos, just so you could see what was going on in the human world. You don't have to read Lovely Chaos to get this.