Quote
"The man Leia called Father was obviously not her father. He is part of the group that ends up having to fight Darth Vader in the film that will be out in 2003 [laughs]. The part that I never really developed is the death of Luke and Leia's mother. I had a backstory for her in earlier drafts but it basically didn't survive. When I got to Jedi, I wanted one of the kids to have some kind of memory of her because she will be a key figure in the new episodes I'm writing. But I really debated on whether or not Leia should remember her." - George Lucas: The Annotated Screenplays
"From the very beginning everyone asssumed that Padme would survive all the prequels because she had to live long enough for Leia to remember her."
Actually, I was sure she would die. Lucas downplayed so many other small details, and there was nothing else for her to do in the OT (which is why he killed off Obi-wan in ANH.) Besides, it's really not a continuity error - Leia's images of her mother simply aren't based on what she saw immediately after being born.