I think Rey has to be Luke's daughter.
- She can't be Han & Leia's. It would be ridiculous for Han and Leia to focus solely on Bringing Ben back to the light while having just found their long lost daughter. They don't mention losing her and Leia would be force sensitive enough to know she's hugging her own daughter. There seems to be some kind of connection to each of them, but that seems more befitting a niece than a daughter.
- While I kind of like this concept, it also seems far fetched that she's a Kenobi. We've skipped a whole character/family/generation between Obi-Wan and Rey, so this would basically be about the same as a "she's not related to anyone" if it turns out to be true. If Obi had a son/daughter, then they'd almost certainly be force sensitive. Where would that character have been during ESB/ROTJ and why would Luke be their "last hope?" Seems like a pretty big backstory to conjour up and fairly out of character for Obiwan anyway.
- I don't buy that she's Kanan or Ezra's kid. I think Disney plans for loose, minimal ties back to the Rebels storylines. If we had heard more than Easter Egg references to the Rebels cast in Rogue One, then I'd give this more of a chance, but it feels like too big of a leap from the cartoon to the big screen. Besides, don't Kanan and Hera have something going on? Rey sure doesn't look Twi'lek to me.
- It's certainly possible that she's not related to anyone or was even conceived by the force, similar to Anakin's backstory. NEight of these would be very satisfying though. People are too closely related throughout the SW saga for her to just be some random person, and the force just creating a person was hard enough to swallow the first time. Can't imagine they would go back there again.
Rey clearly has a reaction to touching a blade that's been in both Anakin and Luke's possession. She's apparently 19, which is the same age Luke was in ANH. If my math is right, he would have been about 33-34 when Rey would have been conceived, which is a good fit. She also seems pretty powerful for never having been trained - another trait among Skywalkers. The biggest question mark is how Luke could knowingly leave Rey behind. But what if he doesn't even know she's alive? Whoever the mom is, she might not have told Luke. Or maybe he knew of his child, but thought she also died in the chaos that sent him into exile. Another consideration is the whole concept of attachment for the Jedi. We know that attachment leads to fear of loss and fear is the path to the dark side. Maybe Luke felt that maintaining any kind of attachment to Rey could drive him to the dark side, so the lesser evil was abandoning his daughter and going into exile rather than unleashing another Darth Vader on the galaxy. That might explain Snoke and Kylo's reaction to "the girl," possibly realizing she is the long lost daughter of Luke.
We talked about the coincidence of the Falcon being on Jakku, but I actually think the bigger coincidence is Lor San Tekka's presence. What are the odds that a close ally of the New Republic and follower of the Church of the Force is hiding on Jakku as well. The same guy who has the missing key to Luke's whereabouts. I think Lor is on Jakku watching over Rey the same way that Obi watched over Luke. Maybe Luke entrusts Lor with both his kid and his whereabouts, and Lor finally gives up Luke's location because the First Order is poised to become a bigger threat.
