As far as we know the Twilight vampires don’t exist on this Earth in this particular Universe. However if they did it’s possible that they are the product of the mating between a sparkling fairy, and a vampire which is impossible in this reality. There’s also a possibility of a demonically possessed fairy somehow turning a human into a Fairypire, or a half-fairy half-vampire. Again this is another being that doesn’t exist, and it’s very unlikely a demon would possess a fairy since they rarely possess other paranormal beings.
There’s also a possibility that the Twilight vampires are extremely powerful. That the sparkling is in fact micro combustion points on the skin that heal almost instantaneously. Real vampires burst into flames in the sunlight at varying speeds depending on their age, and generational status. Since hypothetically Edward, and his merry gang of gentle vampires heal so quickly they never fully burst into full on unholy flames in the holy sunlight. Although I would think some minor pain would occur, or maybe they’re so pain resistant that it just tickles. Either way I’d care not for Edward, and his ilk to stare longingly at me while I’m sleeping because it’s quite creepy.