Why not both? Assuming Obi-Wan’s child was a woman, then Rey can be both a Skywalker and a Kenobi. She does echo some of Anakin’s themes, too. I think the idea of someone who may bring balance to the Force having Jedi and Sith grandfathers, and being the struggle between the two (both internally and externally, through her battles with Kylo Ren) is fitting. She doesn’t have to be only one or the other, after all:
Only Sith deal in absolutes.