Don’t know if this has been said before but I have a sneaky feeling Rey is the child of Q’ira. Darth Maul created life ala Plaeguies. Don’t say much on the site anymore just thought I’d chime in with my theory after reading some of your thoughts.
I believe that the story arc of Rey’s parents are finished. Rey even told Ben that she knew they were nobody the whole time deep inside her, despite that she didn’t want to believe it. Daisy Ridley even confirmed in an interview with Rolling Stone a couple of months after the release of The Last Jedi that the revelation of her parents in VIII is what she was told from the beginning when she signed on to the trilogy. I personally like the direction of her parents being irrelevant, but I’m sorry to you and anyone holding on that she was related to a familiar character from the past.