You’d think, given what a gauntlet the first film was, the Star Wars cast all became deeply bonded. Most of them did, and all the main Star Wars actors spoke very highly of each other, but Carrie Fisher and James Earl Jones actually didn’t become fully acquainted until much later.
Despite their Star Wars characters, Princess Leia and Darth Vader, having several scenes together, Fisher and Earl Jones only shared a set decades later. They both appeared in an episode of TV series The Big Bang Theory, called ‘The Convention Conundrum’ where the crew goes to a con.
CinemaBlend states that showrunner Steve Motaro told an audience during San Diego Comic Con in 2014 that they incidentally hosted Earl Jones and Fisher finally uniting proper. Apparently when they saw each other, Fisher exclaimed, “Daddy!”. Aw!
This may sound odd, and perhaps a little far-fetched, but Star Wars movies back in the ’70s and ’80s were far from the blockbusters they are now. A New Hope itself was a very troubled production, and James Earl Jones only provided voice-over, something that’s almost always added in post-production well after the other stars have finished.
David Prowse was the one in the costume for Vader. Therefore, Fisher and Earl Jones were involved at different stages, hence they didn’t run into each other while filming The Empire Strikes Back or Return of the Jedi. However, it seems like bad coincidence they never crossed paths at any of the premieres for the action movies.