I think that the child will be half werewolf and a quarter human and vampire. It will have human skin, but be exceptionally warm, warmer than Jacob and Renesmee put together. It will have vampire abilities, like super-speed and strength and a vampire gift, and it will have the choice between blood and human food. But at the same time, when it grows old enough, it will be able to change into a wolf like the other wolves, depending on how fast it grows. And that's pretty dangerous. A vampire who can change into a werewolf- that would mean vampire strength multiplied by werewolf muscle. Any child of Renesmee and Jacob's would be badass.
i think if they have a girl shell be biracial of course but look like renesmee and be half vampire half werewolf and if they have a boy he will look like jacob and be half vamp half wolf like his sis.