WHO is Rey?

SPOILER ALERT for those who have not seen the latest Star Wars! If you are one of these people, you ought to be ashamed of yourself! Now go straight to the movies!

Are you back? Okay. Continue reading now.

You are probably asking yourselves the same question as everyone: WHO is Rey? Where does she come from? Who are her parents? Now, no one can know for sure, as it is not mentioned explicitly in the movie. However, some clues inserted in the film can help us speculate.
As Rey is force-sensitive, it would make sense that she has ancestors that were force sensitive. Usually this "trait" or "gene" is transmitted from generation to generation (for example the Skywalker family). We know that "The Force Awakens" takes place 30 years or so after the battle of Endor. At this time, the only remaining Jedi is Luke, and her sister who is also force sensitive. So Rey is either Luke's daughter or Leia's daughter. She could also be a random force-sensitive character, equal to the padawans (recruited by the jedi) of the prequel trilogy, but it doesn't seem very probable, given what follows. There are many arguments to prove each point, so now I present to you the two theories!

The first theory is that Rey is Han Solo and Leia Organa's daughter. Now, we know she has been on Jakku for a very very long time, probably abandoned there as a child. In her force vision at Maz Kanata’s palace, she is seen as a little girl looking at a leaving spaceship. If that is the case, Han most likely does not know about Rey being his daughter, for he would have realized it during the time they spent together (most of the movie). As in Star Wars, history keeps repeating itself, Leia might have wanted to hide Rey form the First Order to protect her, just like Luke and Leia were hidden from Darth Vader. Also, we know Kylo Ren (born Ben Solo) is Leia and Han's son. Don't you think the names Ben and Rey look and sound the same? If this theory is true, the two are actually brother and sister. Maybe, just like Luke and Leia were twins, Rey and Ren are twins, and it would make sense that they both bear a similar name. Another major argument is that Rey manoeuvres perfectly the Millenium Falcon without previous experience. She herself seems amazed that she managed. This could prove that a part of Han Solo's piloting instincts were given to her. If this theory is correct, Rey got her Force sensitivity from her mother Leia and her amazing piloting skills from her father Han.

The second theory is that Rey is the daughter of Luke, the lost Jedi. If that is true, her Force sensitivity comes from him. First off, we can say she pretty much had the same history as Luke: she grew up on a desert planet, Jakku, just like Luke who grew up on Tatooine. Then he leaves the planet... aboard the Millenium Falcon! Throughout "A New Hope" and "The Force Awakens, Luke and Rey discover the force and learn to harness it. Both movies end with them having defeated the Dark Side: Luke blows up the first Death Star and Rey wins her duel with Kylo Ren. They both use the force to accomplish it. These similarities between their paths could be clues that they are actually father and daughter. Furthermore, during the scene in Maz Kanata's castle, the great connection between Rey and the Skywalker lightsaber is revealed: it is as thought the lightsaber "recognizes" her as being part of the Skywalker family. We know very little about Maz Kanata and how she is in possession of the saber (lost by Luke in "The Empire Strikes Back"), but it is clear she has great knowledge of the Force. We also know she is more than a thousand years old, so she has lived through the events of the prequel and original trilogies. She probably has information on Rey's parentage, and will become very important in episodes 8 and 9. In ending scene of episode 7, we do not know if Luke recognizes Rey, so maybe that part was left out for a reason: to create suspense for the viewers.

There is also another possibility: Could Rey have been conceived by midi-chlorians, just like Anakin Skywalker (episode 1)... Maybe, who knows?
Tell me what you think is the most probable theory in the comments!