The most popular (and puzzling) question to come out of The Force Awakens is: who are Rey's parents? There are several theories. First, many indications point to Rey being Luke's daughter. Both were raised on desert planets, both discover they have mad Force skills, and Luke's original lightsaber called out to Rey specifically. At the end of TFA, as Rey is holding out said lightsaber to Luke, he knows her. You can see that, right? As for Rey's yet-to-be identified mother, Laura Dern has joined the cast of VIII, and there are theories regarding who she'll play. She could be Mara Jade, who was Luke's wife in the Expanded Universe and also the assassin known as the Hand of the Emperor, which may or may not intersect with the current canon. Dern could also be any other number of characters we don't yet know about. In any scenario, she could still be Rey's mother.
Luke could also just be Rey's uncle. A big speculation is Rey is Han and Leia's daughter, who somehow has been kept secret from brother Ben Solo, after he goes all Dark Side-y and turns into Kylo Ren (i.e. she's born after Ben goes off to the Jedi Academy and he doesn't know of her existence). Kylo certainly has a connection with Rey when he tries to mine her brain for info, and both Han and Leia seem immediately drawn to Rey when they first meet her.
Here's our take if the Han/Leia/Rey connection is real: Only Leia knows the truth and has kept Rey a secret even from Han, who probably left before he knew Leia was pregnant. If you notice, the late smuggler (*sniff*) did connect with the young woman, but he really didn't register too much emotion when he saw her for the first time. If he knew she was his daughter that would be unusual. Han wore his heart on his sleeve most of the time, and was torn up about Ben/Ren. It's hard to imagine how he could keep that cool the whole time he was with Rey.
Watching Leia, however, is quite different. The General shows restraint, yet when she meets Rey, something else is happening. You can feel it. Then, when she hugs Rey after they return from destroying the First Order's Starkiller base where Han was killed by Kylo, it seems like Leia knows this young woman very well. Again, it could be a grief thing or an aunt thing, but…
Other theories include Rey being of Kenobi descent, as in Obi-Wan's great-granddaughter, or perhaps has no connection to anyone we know at all, or even a virgin born, like Anakin Skywalker—or even crazier still, she's a reincarnation of Anakin. While these could all be possibilities, we still feel in our hearts that Rey is indeed a Skywalker, even perhaps the mythical Chosen One (like Anakin). If we were to speculate, she'll train with Luke for awhile, much like he did with Yoda. Then, Finn or someone like that will get into trouble and she'll have to race off to save them. Eventually, she'll either confront Kylo Ren or Snoke or both, win, and assume her rightful place in the Force. Does this all sound familiar? Let's hope they surprise us, at least a little.