No I don’t think it’s just Rey at all. That’s one of the biggest points of the final scene of TLJ, showing that this is a potential that lives in many (random people) throughout the galaxy. I hope TROS delves into this aspect in some regard.
In the larger sense, in terms of what I’m explaining, it’s my interpretation and I think it’s good that it’s left to interpretation. In my mind where Rey gets her powers from doesn’t matter so much as what she chooses to do with them.