I am more and more convinced that Rey is Han and Leia's daughter. We know Fynn crashes his TIE on that dessert planet (forgot the name) and meets Rey. From all the trailers combined, we now know that a bunch of TIE will attack them, we see the settlement on that planet under attack and Fynn and Rey running from explosions. On that same planet we see the Falcon being chased by TIE's. The shot in an earlier trailer of Han saying 'Chewie, we're home' seems to imply he hasn't been on the Falcon in a while, so it's not he suddenly popped up with the Falcon. Implying that it was on the planet.
Now..... Family ties have been hinted and teased at by the production team. Even in a recent interview with Kathleen Kennedy (
http://www.joblo.com/movie-news/we-...liar-faces-in-star-wars-the-force-awakens-301), comments were made on how twins COULD run in the Skywalker family.
I'm saying, a bit similar to Yoda and Obi-Wan hiding the twins from the emperor and Vader, Han and Leia decided to hide Rey from some evil/destiny. Rey is aware of her parentage, and the Falcon was left behind if she ever needed a quick get-away from that planet. It's Fynn flying it during the chase, I think.
Anyway, my two cents.