■ She is naive. She is confused. She does not understand the world
Nope.
She's the character with the most clear purpose and objective. Other characters, like Finn, are far more confused, not to mention old Luke 'green milk' Skywalker. They don't know what the hell they're doing. Rey is indeed the only character (besides Leia, another female) that knows exactly what she wants to do.
■ She has no family
That's no serious weakness. No character in the whole 9 movies had any family support. Luke and Leia even saw their family die in the first OT movie.
■ She has weak, thin arms
Nope.
Remember Force Awakens beginning scene, with her fighting stormtroopers with a fucking stick and saving Finn. She's a modern super-empowered woman, as strong as any man (and probably more, because she has a super-vagina).
1) Rey isn't a character, she's a preteen coming-of-age female power fantasy.
2) Rey is the product of gynocentric group think and confirmation bias.
3) Rian may have received lead writing credit, but Rey is the collective product of a collaborative hen house.
4) Rey's only 'struggle' in the trilogy is the quest for the understanding of how she came to be so amazing.
5) Rey will assume the official mantle of 'goddess' in the final installment, at which point she will formally graduate to cartoon superhero.