You make a compelling case. I almost want to place a check next to this theory. But for me I still think she is a Skywalker. We’ve been disconnected from Luke for so long we don’t know what happened to him after Return of the Jedi. The other thing that makes me believe that she is a Skywalker is the final scene with her returning the light saber. Luke was given that by Ben. Also her being left on that planet by her family is very much like her father’s beginnings. Their are way too many similarities but hey…I can’t wait until for the next installment.