To be fair, we didn't really know what Luke's abilities were. We saw him deflect three blaster bolts. Then we saw him "use the Force" instead of his computer to make a shot on the Death Star that was "one in a million" (and which we'd already seen couldn't be done with the aid of a targeting computer). Oh, and we saw Vader say "The Force is strong with this one..." Luke also mentions bullseying womprats in his T-16 back home, which was later interpreted to be evidence of Force abilities or something, but it's said in passing and never really explored within the film.
How is any of that "earned"? For that matter, how is it any more earned than Rey's apparent abilities?
All I see with Rey is that she's able to do some stuff without understanding it really. She's clearly strong in the Force. Probably as strong as Luke, or maybe stronger. She doesn't understand her power, and she's not really in all that great control of it.
But both of them had equal "earned" abilities from what we saw in their respective first outings.
Oh, and this all says nothing of Anakin the Messiah who has stronger midichlorians than even Master Yoda, and who apparently can do what LITERALLY NO OTHER HUMAN CAN DO in flying in the pod race, at the age of NINE, all because "Well, the Force, duh." And then he goes on to pilot a starfighter in the Battle of Naboo, blow up a Trade Federation droid control ship through dumb luck (or the Force), and somehow survive it all, without any benefit of training. Not even a single session with Qui-Gon saying "Close your eyes and feel the Force" like the other two had.
They're all powerful. It's weird an unexplained and hereditary, as we later learn (except Anakin, whose Force sensitivity could have been manipulated somehow or something). They all pull off amazing feats through the use of the Force in their first, untrained outings.
That's the point. They're powerful for a reason within the narrative, not just as a plot solution.
Mary Sue/Marty Stew/Gary Stew characters usually exist as a form of wish fulfillment for the author (and often serve as the representative of the author). Their powers usually manifest in some "Get out of trouble free" way, kind of like Batman's shark repellent or James Bond's gadget that was given to him by Q which serves no purpose other than to get him out of this exact situation.
Rey is powerful because it's part of her backstory, her identity, all of which has been created as a mystery (to us, the audience). Is she more powerful than Vader? Or Luke? Or Obi-Wan? It's unclear. We don't know the extent or limitations of her power because we know next to nothing about her.
Look, I agree that Rey's ability with the Force is surprisingly strong. I think that's done on purpose to lampshade that there's something mysterious and special about her, which will be explained later. I'd also venture that we'll discover that Rey has some inner flaw or weakness as well that she will have to overcome, since, you know, that's a pretty classic part of the hero's journey.
None of that = Mary Sue. Merely being powerful does not = Mary Sue. Being powerful for no reason other than wanting to have a powerful character who can do anything = Mary Sue. But that's not what's happening here.
If you just don't like the movie, I mean, cool, it's art, and art's subjective. But if you're gonna claim that she's a Mary Sue, you're either missing what's going on, or intentionally ignoring it. Either way, the claim is wrong on the facts.
IT COULD END UP BEING PROVEN TRUE LATER IN THE SERIES. I will grant you that, certainly. If the writers of the next two films don't effectively explain her extraordinary abilities, show her struggle with them, etc., then yeah, she could arguably be called a Mary Sue. But not in this film. In this film she's a hero with a mysterious backstory. That's it.
