1. Vampires Breeding
In folklore, the vampire's first victim would be his wife, (if the husband had died and came back a vampire).
The widow would then be pregnant with a child called a dhampir, (half vampire and half human).
People say it is impossible for a vampire to reproduce, and the fact Twilight screwed it up.
The author of the series never read about vampires, but the fact vampires can reproduce, though due to them being dead, (so how can that work?) had not been explained.
So if a corpse can come to life as a vampire, (or if someone can be turned), can't their seed/egg?
In The Vampire Diaries, a witch can't be a vampire and still be a witch. As witches are connected to nature, the vampires are destructive. They are the complete opposite to each other. Vampires in the series cannot reproduce either.
In the book series of Oliver Nocturne, it is possible to have vampire offspring. As these babies can only be made in test tubes. It is very rare for vampires to be bitten as babies and children. Vampires in the series do in fact age, but it takes centuries.
So you see in some forms of fiction, reproducing cannot be done, but to others, it can.