New images from Star Wars: The Rise of Skywalker show Luke (Mark Hamill) and Leia's (Carrie Fisher) extended lightsaber battle. Fans were surprised to learn there was a time when Luke began to train Leia to be a Jedi, though she gave it up after learning her continued training would lead to devastation for her son. This was revealed in The Rise of Skywalker, which features a quick flashback of a young Luke and Leia sparring together. CGI was used to de-age Hamill as he stood in for Luke, but since Fisher tragically passed away in 2016, her daughter Billie Lourd stepped in for Leia. Lourd also had a small role in the new trilogy as Lieutenant Connix.
Fisher's passing disrupted the plans put in place for Leia's trilogy story. While the first two films of the reboot trilogy included expanded roles for Han Solo (Harrison Ford) and Luke, The Rise of Skywalker was supposed to have a larger role for Leia. Instead, director JJ Abrams had to make do with eight minutes of unused footage from previous films to craft Leia's ending. The flashback represents one of the final moments Leia is seen onscreen in The Rise of Skywalker.
As part of the special features included in The Rise of Skywalker's home release, new images of Luke and Leia's training session have been made available. The scene itself is short, though it was originally much longer and ended up trimmed down for the final cut. For reference, Luke wields the green lightsaber while Leia has the blue. As the pictures indicate, the full training scene included a bit more action. You can see them below:
Despite favoring politics over the ways of the Jedi, Leia demonstrated her ability to use the Force multiple times throughout the new films. Through the Force, Leia was able to sense when both Han and Luke died, and, perhaps most controversially, she used the Force to save herself after she was sucked into space during Star Wars: The Last Jedi. The Rise of Skywalker was the first time it was confirmed that Leia nearly became a Jedi, however.
Like much of The Rise of Skywalker, Leia's ending proved divisive among some fans, though that could be attributed to the lack of options available to Abrams and his team. It can be argued that they did the best they could under the circumstances, though it's hard not to be disappointed that Leia didn't get her due. However, The Rise of Skywalker still managed to reveal something new about Leia, much to the amazement of fans.
Source: Star Wars: The Rise of Skywalker home release