One thing The Last Jedi's trailers have made abundantly clear is that the movie will be underpinned by grey morality, unlike the Sith, who deal only in absolutes.
In keeping with this, Rey will be consumed by an inner conflict that will pull her between the Force's light and dark sides, and the trailers have depicted her flirting with both polar extremes while offering no hints about which one she'll ultimately embrace.
The preview footage has already confirmed that Luke Skywalker will offer her training (though not in the ways of the Jedi per se) but also teases a rift in their mentor-student bond, likely the result of Rey exhibiting similar traits to Kylo Ren.
The trailers have added to the intrigue surrounding her destiny by revealing that Kylo offers his hand in friendship, but there's no guarantee Rey willingly takes it, since there's another scene in which she's being tortured by Snoke.
Will Luke's student return to the light after falling out with her mentor, or will Kylo Ren and Snoke steal her away to darkness by any means necessary? Based on the grey ideals The Last Jedi appears to be trading in, perhaps the truth is a little of both.