I ran across
this theory on Tumblr today which posits a very interesting question.
To wit, what if the "family" who left Rey on Jakku was Kylo Ren, after he couldn't bring himself to kill her?
Now, I'm not 100% in agreement with all this person's points, but some of them are mighty persuasive, not least being:
Unkar was not a guardian - she was practically trapped in a role as an indentured servant with barely enough to eat. Does this strike you as a situation a caring parent would leave their child in even temporarily? I don’t care how desperate the parent was - there’s no way they couldn’t have found someone more suitable to look after her. No, this, to me, looks like something a stupid, panicking teenage boy would do who’s in way over his head.
I haven't mentioned it in my previous post or any of the comments because I hadn't made it make sense in my head, but Rey's stubborn, dare I say compulsive, insistence that she has to stay on Jakku has the ring of a belief imposed on her from outside. I haven't been able to come up with a scenario in which I can buy that being Luke's doing, but the ham-handed work of panicky teenage Kylo? Absolutely. And I can also easily buy him tampering with his own memory to further erase the evidence of his betrayal/failure.
There are logistical issues that I'm having trouble seeing a way around at this point, particularly how/when -- presuming this is his little cousin we're talking about (I'm not convinced they're siblings, but it's still plausible) -- he got to Han and Leia and Chewie too.
But it's interesting, and I figured some of you would think so too.