So, we've all seen Star Wars 7: The Force Awakens right? If not then there's a major SPOILER WARNING in effect for this entire article, and I'll say no more than that.
Now, if you've watched the new film, you will know that the majority of background time spent on our new characters was for Kylo Ren. While finding out that he was the son of Han and Leia was a major reveal, it was common enough knowledge to the characters in the film already. However we didn't get any insight into the identities of either Finn or Rey's parents. While there are many theories about Finn being the son of either Mace Windu or Lando Calrissian (which also happen to be the only two significant black characters thus far) there isn't enough to go on to guess anything about his heritage. However the film gave us several tips into Rey's, and there is a lot of speculation about who her father is particularly. One such theory is that Luke Skywalker himself is her father, and there are a lot of reasons this is a very possible, even likely, answer to the question.
1. Fighter Helmet
FOR: The fighter pilot helmet beside Rey in this photo is supposedly one of the only relics left to her by her family, who left her on Jakku. While it looks very similar to Luke's own helmet worn by him in the original trilogy, there is a problem with this.
AGAINST: For starters, this isn't necessarily Luke's, as many rebels wore similar or even identical helmets. Also, if Luke brought her to Jakku himself the question is why would he leave her there? It doesn't make any sense at all. The majority of theories suggest that Rey's mother left her on Jakku. Could her mother have given her the helmet that Luke left with her? Possibly.
2. Natural Piloting Ability
FOR: Rey is an accomplished natural pilot, and that is very similar to the ability Luke and Anakin shared. Anakin was piloting pods at a very young age, and was always considered accomplished in this area, while Luke destroyed a Death Star the very first time he got into an X-Wing.
AGAINST: This is possibly just a trait relating to force abilities, which the three of them also share.
3. The Lightsaber Called To Her
FOR: Rey obviously had some connection to the lightsaber for it to bring on such a powerful vision. In addition, she saw Luke sitting with R2D2 in the vision, which was not related to the lightsaber itself in any way, it merely happened to Luke. Did the lightsaber bring on memories from itself or memories of Luke because Rey had a link to him?
AGAINST: This could again be her force ability sensing Luke's through the saber.
4. Maz Giving Her The Lightsaber
FOR: Maz wouldn't give away this precious relic to just anyone. It had to be someone she trusted to give it back to Luke. She clearly trusted Rey, and knowing so much about the force, she probably felt the presence of a Skywalker.
AGAINST: Or she merely felt that Rey was strong with the force and trusted her. Also, failing to give it to Rey, she settled for Finn, so she may have been trying to get it into the hands of the Resistance instead, hoping they would find Luke.
5. Stronger Force Ability Than Kylo
FOR: Rey was able to beat off Kylo with absolutely no training, and barely even the knowledge that she had any force ability. Kylo was shown to be very strong in the force, and had been training in the use of it for years, but when he tried to find the knowledge in her head, she got more knowledge out of him. Ren's training in the dark side is not yet finished, but he should be able to beat someone totally untrained in the ways of the force. It seems Rey must be stronger than Kylo naturally, and that may well be because her lineage is more in tune with it than Kylo's. If Kylo is so strong with only the ability from Leia, then surely Rey would have to have a parent who is stronger than Leia? Luke is the only known viable option for this.
AGAINST: Of course it could be that the force has actually awakened, and in itself has become more powerful, giving more ability to those with it. It could be that everyone has become more powerful, including Leia, Luke, Snoke and anyone else that had the ability before it awoke. Also it is possible that there are other options for people with more force ability than Leia, we just didn't know about them in the original trilogy.
6. Kathleen Kennedy
FOR: In an interview before the film even came out, Kathleen Kennedy, president of Lucasfilm, said that "The saga films focus on the Skywalker family saga." Now, [Star Wars: Episode VII — The Force Awakens](tag:711158) still had both Luke and Leia in it, but to a minimal degree. It seems like, if this really was a film about the Skywalker family, it was one about the next generation, and that seems likely to mean Rey, who was without a doubt the main character in the film.
AGAINST: Kennedy could have been starting an early misinformation campaign to convince people that Rey is Luke's daughter so the surprise will be all the bigger in episode 8 when we find out she isn't. Or she could have been referring to the fact that this film is about the search for Luke Skywalker.
7. Disney Infinity
FOR: Just today a video was released showing half an hour of gameplay for the Disney: Infinity game with characters soon to be released from Star Wars 7: The Force Awakens. In the footage, Kylo Ren turns to Rey and shouts "Face me..." and the next word is hotly debated to be either "cousin" or "curses". I haven't seen the video, so I cannot judge for myself which it is, but the fact that Disney removed the video incredibly quickly shows that they don't want it to be further analysed. It seems that Disney may be trying to keep this secret until the next film is released.
AGAINST: It is likely that it was "curses" which Ren said. In addition, Disney could merely be trying to squash any rumours flying around, as they don't want to make it seem like they are confirming Rey is Luke's daughter so that it isn't cheating if they reveal that she isn't. Or they could be trying to convince us with this that she is his daughter, so the reveal that she isn't is all the greater!
Thanks for reading guys! And if you're looking for more Star Wars fan theories, click on the big blue follow button below!