Catherine Cullen is Carlisle's biological daughter with his first wife before and after he was a vampire and before he met Esme and fell in love with her. He left her when she was 8 when he met Esme and was already a vampire, Catherine is a hybrid very much like our dear Renesmee but with slow growth, Carlisle didn't give it much thought but what happens when she is reborn after being killed while working for the Volturi, as our dear Bella Swan's cousin? #Wattys2016