Carrie Fisher’s untimely passing left a void in the Star Wars universe. J.J. Abrams said he wouldn’t use digital effects to include General Leia in The Rise of Skywalker, and this left people scratching their heads over who played her during the Jedi training scene.
Buzzfeed reports that J.J. Abrams chose Billie Lourd to play General Leia after the scenes that revealed Leia was indeed a Jedi — which explains why she was qualified to train Rey.
The special effects team needed someone whose face was similar to Carrie Fisher’s so they could superimpose the actor’s face into the footage. Lourd was the obvious choice for duh reasons.
Lourd also played Lieutenant Kaydel Ko Connix in the Skywalker Saga (that’s what these last three films are called, FYI). Lourd and Fisher had several scenes together in The Force Awakens and The Last Jedi because Lourd wanted her future children to someday be able to see her and their grandmother at work together.