That detail wasn’t in any of the movies so the line in ep 6 still makes sense the way you thought. I’m pretty sure anyone would assume that’s what she meant, since we never hear that she knew she was adopted. Whoever made Bail’s wife die in the explosion of Alderaan is the one who messed up, or Lucas ignored that addition when making episode I.
I just assumed she meant her adopted mother, Mrs. Bail Organa. Or did I miss something here?
Edit: nevermind, just looked it up and Breha died on Alderaan when the Death Star blew it up. Lame.
That detail wasn’t in any of the movies so the line in ep 6 still makes sense the way you thought. I’m pretty sure anyone would assume that’s what she meant, since we never hear that she knew she was adopted. Whoever made Bail’s wife die in the explosion of Alderaan is the one who messed up, or Lucas ignored that addition when making episode I.