I think if you’re going to have Padme give birth, it should be Luke she gives birth only in ROTS, then edit it to where we see Yoda, Bail and Obi-wan sitting down talking, but have them mention just the boy.

If you wanted too, you could do a flashback to Padme giving birth to Leia, when Luke finds out from Obi-wan that Leia is his sister, with a voice over by Sir Alec Guinness.

[Showing Leia being born] "The other, Yoda spoke of, is your twin sister…to protect you both from the Emperor…you were hidden… [showing Bail Organa with his wife on Alderaan.] “That’s why your sister remains safely anonymous.”

I also wouldn’t show her death in ROTS, I would have left her in a coma and sent her to Alderaan with Bail Organa and Leia. She could be like sleeping beauty in a chamber and her daughter could see her, but that’s it.

I would like to see somebody do this in a edit for Return of the Jedi, or at least just that scene.