That crossed my mind, as did Luke but I don't think that her parents are cannon, and honestly I'd prefer them not to be. (I don't think Anakin or Luke were the Chosen One either.) That would be the most revolutionary angle by far. The biggest plot twist would be that her parents are non-cannon because everyone is expecting it, and it doesn't really add any interest, or progress the over all story... we're going to what, watch a family feud unfold for 600 years? Patterns need to be broken for progress, as a character she's dynamic enough and I don't feel like any ties to the Skywalker line will really add any dimension, her being something new and different however incites curiosity and intrigue. For me it would make sense that Reys abilities are a natural result of the force being out of sorts, and that she'll bring balance to the force by becoming neither Jedi nor Sith, possibly even pulling Kylo Ren into a place of internal balance, and destroying the entire construct of "dark side" and "light side" and along with it both orders (though the Jedi order doesn't seem to fare too well any way does it?) and fulfilling the prophecy that way.