Alright I've got to say this because I've looked and haven't seen any one else mention it yet. In Eclipse, we find out that Embry Call's mother is from the Makah tribe thus Jacob, Sam, or Quil has to have a half brother. No more explanation is given. In Midnight Sun when Edward and Carlisle are making a false trail for James to follow, they rent a boat to ferry them across into Canada from members of the Makah tribe. The older of the two, Albert, asked Carlisle if he knows Billy Black. Carlisle answers that he does as well as Jacob, his son. To which Albert asks what about his other son? Carlisle responds that he wasn't aware Billy had another son and Albert begins cackling. His thoughts are disjointed and Edward can't quite follow his train of thought to follow what this is in reference to, however he catches the words "Allycat" and "Grandson". Robert, Albert's son and other ferry man, makes his father stop without offering explanation to the Cullens. His thoughts revolve around that "Lily" is happy out there and no one cares anymore. Edward infers that "Lily" may be Robert's sister. The wiki says that Embrys mother's name is Tiffany so maybe Lily is a middle/nickname or vice versa.
