I couldn't say about all of Star Wars, since I've only seen the original IV-V-VI trilogy... in their original form, before Lucas started mucking them up. I tried watching the other three, but found them so boring, I couldn't stay awake long enough to finish them (honestly). I do remember being annoyed at the retcon concerning Leia and her mother. In Return of the Jedi, she states that her mother died when Leia was very young, but that was changed in the chronologically-earlier movie. They both can't be right.
She may have had a nanny who cared for her while her adoptive mother, the Queen, went about her duties. To further obfuscate her origins once the nanny died they may have told Leia she was her biological mother. A falsehood that would keep her from looking too closely and dangerously into her adoption.