Board Thread:Show-Related Questions and Answers/@comment-32752777-20170807173716/@comment-25375217-20170807174627

Well... yes and no. Yes, she is Princess Leia in the Once Upon a Time book. No, she does not fill the role of the Princess Leia Organa from the Star Wars series. Emma is mostly an original character with ties to the Black Swan from Swan Lake and the Ugly Duckling from The Ugly Duckling.

You could stretch it to say Rumple is Darth Vader, Milah and/or Belle is Padme, Baelfire is Luke, Emma is Leia, Hook is Han, etc. but that's probably not the intention of the writers and is definitely not canon.