Rey is a human female, abandoned as a child on Jakku and raised there as a scavenger. She was introduced in Star Wars: Episode VII The Force Awakens (2015) and is played by Daisy Ridley. The Rise of Skywalker (2019) established her as Palpatine's granddaughter, and closed with her taking the Skywalker name.
The parentage argument
The sequel trilogy changed its own answer about who she is between films, and the novels have had to live with the result. It is worth reading the three film novelisations — The Force Awakens, The Last Jedi and The Rise of Skywalker — back to back purely as a case study in tie-in fiction absorbing a course correction: each one is internally coherent, and together they are not.
Where the books help
The most useful Rey material is not the novelisations but the surrounding fiction — the Jakku years — Shadow of the Sith is the essential one — the Resistance-era young-reader books, and the Marvel comics that give her actual training scenes. The films tell you she is powerful. The books are where she is shown learning, which is the part that makes the power tolerable.
Canon only
Rey exists only in current canon. Star Wars Legends ended its timeline long before the sequel era and never contained her; the Legends far future belongs to the descendants of the Solos and Skywalkers instead.
Reading note
Her arc is the first in the saga where the central question is inheritance rather than destiny — whether you are obliged to be what you came from. The Legends shelf, obsessed with bloodlines, would have answered that very differently.
