a bleg for information that I don't care to wade around the google for

people who have read TFA tie-in materials: do we get any indications about which of the OT secrets have been told, and to whom? Mostly, I'd like to know a. who knows that Luke and Leia are sibs, and b. who knows that they're the children of Darth Vader. Am attempting fic; need to know these sorts of things, and the film itself is completely silent on both subjects.