One of the biggest mysteries introduced in The Force Awakens is the identity of Rey's parents. While there is plenty of speculation about who they might be (including our theories), we still don't have a definitive answer. That's going to change with the release of Episode VIII next year.
In an interview with Vulture, actress Daisy Ridley (who plays protagonist Rey) was asked about the possibility of a particular character being Rey's father. She didn't give a firm answer one way or another, but said, "“We will see in a year. Just sit tight on that question.”
Star Wars Episode VIII releases on December 15, 2017, so Ridley's answer implies that the next installment will put an end to the debate of this hotly debated topic.