Yes please!

I think our best option to justify Rey Nobody’s power using existing footage is twofold:

Firstly, imply more training. I’d have Rey with Luke from the beginning of TLJ, to allow more time in-universe to pass until the First Order assault on the rebel base which kicks off the timed plot. I’d try to have as many different scenes of Rey on Ach-To as possible, spread over as much of the movie as possible. I’d try to imply that her training continued in TROS under the tutelage of Jedi from beyond the grave, where possible (you could, at the very least, use the opening crawl).

Secondly, lean into the ‘she’s using the dark’ angle. Luke explicitly says “You went straight to the dark” in TLJ, and we have the accidental lightning scene in TROS - more could maybe be done with effects work, especially that ‘sith rumble’ sound effect, when she’s being particularly powerful.

There’s also the idea that Kylo’s mind probe in TFA goes both ways, and she learns a bit of technique from that, but I think that’s already been solved as well as it can.