Forum:KB:How could Leia knew her mother?

I am wondering why Leia tels to Luke in Ep6 (on Endor) that she remembers her real mother? Padme dies in childbirth, so it is really inpossible that Leia remembers that her real mother (Padme) "was beautiful and sad". Was she talking about the Bail Organa's wife (Breta) or is a movie mistake?