The season 2 episode of “Star Wars Rebels,” titled “A Princess on Lothal,” follows a 15-year-old Leia on a mission for the Rebellion on behalf of her adoptive father Bail Organa to deliver ships from Alderaan to Lothal to help the Rebels. At the time, neither Leia nor Alderaan were officially or openly allied with the Rebellion, so Leia came up with a plan to help the rebels “steal” the ships. During the mission, Leia bonded with a young Ezra Bridger, who is the same age as her, but it is Hera who has the most in common with the young princess. The two of them are not only daughters of prominent resistance fighters, but they both became leaders at a very young age and were forced to grow up on the battlefield.
The mission ended up being crucial to the Rebellion, as the three Hammerhead Corvettes played a big role in the Battle of Scarif — with one of the ships ramming a Star Destroyer in one of the best scenes in “Rogue One.”
As for Leia and Hera’s friendship, we know it didn’t end there. Even if Leia didn’t appear in “Rebels” after that episode, the two remained at least acquainted for years as Hera became a prominent pilot and later a general while Leia took on a more political role. We know this because the canon miniseries “Forces of Destiny” includes an episode set right after “Return of the Jedi” where Leia asks Hera for help in feeding some Ewoks before they start eating captured stormtroopers. Leia may not have gone on many missions with the “Rebels” group, but she is an unofficial member of the Ghost Crew.