No she isn’t. People with Force powers are innately good at stuff. How much time had Luke spent in an X-Wing? And yet he could fly in that trench at high speed and bob and weave and never crack up on the side like we saw multiple almost certainly more experienced (since it’s not possible to be less experienced) pilots. He was also better on the Falcon’s canons than Han. Roll that through your head, better than Han with the guns on Han’s ship. Speaking of better than Han, ever notice Leia is a better shot than Han?
We saw similar with Anakin in the prequels. You forget, Anakin didn’t just have quick reflexes, he could fly ANYTHING, and shoot ANYTHING, better than the people paid to do so. People with Force powers are innately good at everything they do.
Rey isn’t done yet. Now she’s found Luke, who’s going to be teaching her, and (I’m willing to bet money) is going to turn out to be her father. It’s not girl power, it’s Force power. She’s not a Mary Sue, she’s a Skywalker.
Stars Wars cannon dictates it takes decades to master "force techniques" of those who are force sensitive. In IV Luke was already flying aircraft between trenches as he was growing up and target practicing on wombats (As explained). Rey was way more advanced on the outset while never piloting a spacecraft and being oblivious to "the force" at all. So all the sudden she "gains"/learns these powers in an instant in what takes years of those training in the Jedi arts to even attempt to pull off.
All Anakin had in I was quick reflexes, no force powers (And this guy was "off the charts"). Even when pod racing it was mentioned he never finished a race (Always crashed) until the race he won. In II after years of training he still did not have the grasp of force powers and got his butt handed to him (Again, off the charts).
Rey had it all, which leads me to believe either Super Girl/Mary Sue which breaks all sorts of cannon or that she was trained before (Probably under Luke) and was teetering towards the "dark side" thus her memory was erased (Which is just too contrived/convenient to shoe-horn in).