I didnt see any evidence in the movie that says who her parents really are. The two theories are Han and Leia, or Luke and "someone."

>!Han and Leia seem unlikely as you would expect their reaction to a "force sensitive girl being found on jakku" a bit strange and would have to have known who she was.

You listed one point about Lukes saber that could suggest a tie, however the end of the movie suggests an even bigger possibility

>! When Rey finds luke and presents him with his saber, Luke tears up and starts to cry.

We dont ever see a Jedi show that kind of emotion anywhere in the movies. Now, whether its because of Rey, or his lightsaber, is still unknown. Nor do we have any idea who the mother would be at this point.