I'd be more willing to accept the she's-a-Force-baby-and-can-somehow-have-newborn-infant-memories theory than the she's-just-remembering-her-adoptive-mother theory. There seem to be two sub theories in this theory. The first, which is the most insane, in my opinion, is "She never knew she was adopted." Now, let's say that's true for a second. Now pretend you're Leia, and you think the Organas are your birth-parents. Now, all of a sudden, Luke comes up to you and asks, "Do you remember your mother...your real mother?" Now, maybe it's just me, but if I was her, it would certainly cause me to turn my head if I had no idea I was adopted. But you, Shimraa, seem to be of the camp that believes that she simply got her memories confused, which, I admit, is a much more feasible theory. I just don't think so for two reasons. If she grew up with Mrs. Organa, I would think she would be able to differentiate between them. I know, it's a pretty weak argument, but it's all I have. The other reason, which makes much more sense is, that it's cinema. A story is being told. All things that happen in a story should happen for a reason. This scene is one of the pivotal scenes in Return of the Jedi. I might believe it today, but I really doubt Lucas would put such an emotional build on this segment only to have it be complete bull. It doesn't serve the story. I mean, this is Luke getting the first and only description he had ever heard of his mother. It completely ruins the mood of the scene if we believe, "Haha, Luke. You think that's your mother? Leia's just confused. You'll just carry those images Leia described to you for the rest of your life and never be the wiser." If this was real life, we could accept that, but since it is a movie, the only way someone would do something like that is if it were revealed at some later moment. So, in my mind, it's simply another prequel continuity error.

And, heh, I got so carried away that I almost forgot about this, about your theory of Padme living on, who is to say that she would have hidden on Alderaan? She didn't need to be on Alderaan for Bail to adopt her the way things play out in Sith. I fully agree that Yoda and Obi-Wan would have been in charge of where to place the kids when their mother died. And, regardless, Padme had no hand in the decision for Leia to join the Imperial Senate. Leia was much older at the point and was just becoming the successor for Bail Organa, and because she was trying to work some of her Rebel Alliance influence into the Senate. As for Vader finding out, the movies already answer that question. Vader never knew that Leia was his daugher until he plucked it from Luke's mind on Death Star II. There was no reason for him to even suspect that Leia was his daughter, so she was perfectly safe in Alderaan's royal family.