User blog comment:Cullen's are HOT!!!/Renesmee and Jacob (Question)/@comment-2069500-20111213004452/@comment-3217161-20111213041438

But like you said and I quote

"That being said, if (this is a big if) Rosalie, Edward, and/or Bella don't like the idea of their technically child daughter (niece in Rosalie's case) engaging in any kind of intimacy, then I do not believe she will have children. If she did, they would be 2/4 human, 1/4 vampire, and 1/4 shapeshifter. Of course, I'm assuming that because both parents have the human traits compared to single vampire/shapeshifter traits... By my figures, the shapeshifter trait is dominant and vampire traits aren't even able to be passed on. So, the 1/4 vampire is about 85% certain to not crop up because such traits are acquired. If they could be passed on, it would only be slight. The offspring would probably have some sort of sporadic shifting cycle, probably uncontrollable and very weak. They may have a tougher immune system, on the other hand. Depends on probability."