Well I have my opinion on what will happen here. We know Padme lives for a while to help raise Leia so for a short time after Leia's birth (a few years as Leia says she remembers her mother in childhood) we know she lives. Probably hidden for some time and she delivers Leia to Alderran *sp where Leia is raised as the queen's daughter. I can't see Anakin killing her as that would totally conflict with the continuity of the story.