Well, the trouble is that I think my part is truest to the saga as a whole. Which, as the final chapter in a 9-part saga, I think that should take priority. We can focus on the previously unknowns once this saga is over.

Let me try to explain my thought process that led to my original idea right here:

The Skywalker bloodline is freakishly powerful, to the point where the only reason eyebrows weren’t raised in the Jedi Order is because of a prophecy. Nobody has ever, or will ever, be as strong as those in this bloodline.
This prophecy turned out to be a whole load of shit, really. Yeah, Vader finally threw Palpatine down the reactor shaft after 20 years, but this “lasting balance” only lasted for about 20 years because Ben Solo turns to the dark side and 10 years later Palpatine announces his return. Huh?
At this point, the prophecy is more than likely to have been “misread” as Yoda states in Episode 3.
There’s a new girl in town who is freakishly powerful, able to defeat Kylo Ren, who hails from a bloodline that had the strongest Jedi ever on it.
The only way that makes sense is if she has the same raw Force potential as a Skywalker. The only way that is possible is if she were conceived the same way as a Skywalker.
How was Anakin conceived? Some canon lore might state that the light side of the Force did it, but then how come he has such strong dark tendencies? How come his descendants all struggle so much with the dark?
Watching the movies alone, it appears that Palpatine greatly hinted at himself being responsible (the opera show they’re watching is a visual hint, and he gives Anakin that “look” as he describes the process of creating life).
Alright, let’s roll with that. Good news is that Rey can now follow the same origins as Anakin since they both hail from nobodies. Rey’s unexplained powers are finally given a reason, as well as her taking on the name of Skywalker. Rey’s parents can be the dark inverse of Shmi.

Here’s my thought process on why this other idea doesn’t work:

Let’s say Rey is a nobody that isn’t as powerful as the Skywalkers, because no up and coming Jedi should realistically be. Palpatine cannot put his “darkness” into a baby Rey to give her more power and bring her up to parity, because her body simply wouldn’t be able to accept that much power. I also find it strange he would do such a thing. That isn’t in his character to willingly give his own power to others, that’s a Jedi trait.
Okay, so Rey needs to be conceived with all of the power that she will ever be able to harness in life. In order for this to be possible, she must either be genetically related to Palpatine, or a creation of the Force akin to the Skywalkers. We know that no other Jedi has ever been as powerful as the Skywalkers, and we’re trying to avoid a direct Palpatine attachment here.
Yes, anybody can tap into the Force. But to have a complete nobody be more powerful than the Skywalkers flies in the face of their entire saga. I don’t care about “Well, she’s that powerful because that’s just what the Force wanted/intended” because it’s a lazy answer and clearly the Force never gave a damn about the Skywalkers at this point because things wouldn’t have gotten this bad for them otherwise (read my initial points on my idea). It feels like they get a complete and utter shaft in this way. And in their own saga, no less.