The Last Jedi revealed that Rey is not a Skywalker, she’s the daughter of “no one,” i.e. her parents were insignificant.
J.J. Abrams did recently tease that there is more to the story then what was revealed in The Last Jedi, so the film will likely explore her past more in depth.
After the divisive response of Episode VIII, some think the film will retcon some of Rian Johnson’s choices, including Rey’s lineage.
There are some other questions floating around concerning Rey as well though.