My brain might have deleted Rise Of Skywalker from its archives...remind me where she got those? I thought Force ghost Yoda burned them to a crisp using lightning in Last Jedi?
It was during The Last Jedi, not RoS, but don't forget what Yoda said after doing that: "that library contains nothing that the girl Rey does not already possess."
It's supposed to be taken as "She has the qualities needed to create a new Jedi order," but true to Yoda's nature, he's also literally saying that she took the books with her.
You can actually see them in a compartment of the Millennium Falcon during the ending scene, but they're easy to miss:
https://youtu.be/oLp9B2qdQq8
Look at the drawer at about 0:24 in that video.
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(He/Him) I write Naruto Fanfiction. But I am definitely not a furry.