I read this not even realizing it was you, Kenji. It’s an interesting theory, to be sure, and the hardest part (that Sheev was dead about a decade before she was born) is not that hard to handwave. I’m not sure I buy it, but I have trouble buying ANY of the theories about Rey’s parentage, so maybe the curveballiest one I’ve seen yet might be the answer.
My personal theory, which I admit is half-joking and mostly about wanting more continuity with both the excellent tv series, can be summed up in what would be her name: Rey Bridger, House Viszla. Age works, mechanical and piloting talent work, saber style works (Ezra has a fairly aggressive, stabby style), her particular force talents (her first force use is getting into Kylo’s head, and she does the mind trick untrained — this matches with Ezra’s talent of “connection”) work, and you could see her parents turning over their kid to the new Jedi academy and then coming back when it all went south.
It’s highly unlikely, but it’s my pet theory.