Also I believe that Rey has previous training, Kylo somehow unlocked or unhinged this part of her mind, maybe it was also when she touched the light saber and had that vision. But either way she had awareness of the force and knew she could do these things but just wasn't sure how she knew. Learning how to trick someone with the force seems like the first thing a little kid would want to learn and exploit for more blue milk and cookies.
I think Luke mind blocked her and left her on Jakku for her own protection, similar to how he was left on Tatooine. Maybe in this second movie we even find out that she DID have a protector on Jakku but it died, or was left unaware during her confrontation.. or a force ghost was watching over and guiding her. Will Luke have a moment where he talks to Ben the way Yoda did in ESB? "She is to old." "You will be. You willllll beee..."
"In brightest day, in blackest night / No evil shall escape my sight / Let those who worship evil's might / Beware my power, Green Lantern's light!"