If it Lucas Luke and Leia were going to be siblings from the very beginning, I do feel like he would’ve handled it differently. Yes, the trilogy is more so Luke’s story than anyone else’s, but the revelation and what it means for Luke isn’t given the same weight for Leia, even if the implication is pretty much the same.

Of course, Luke idealized his father, wanting to be like him, so discovering what his father became has this consequence of Luke wondering if he could become that too. Whereas when Leia was adopted by the Organas, they raised her as her parents. So I don’t think Leia ever spent much time wondering who her biological parents were, or wanting to be like them. The Organas were enough for her to look up to.

I know the EU and Canon both explore Leia’s feeling on Vader being her father a little, but it could’ve been interesting for the movies to explore that more.