I would agree with the self-reliant part, but I would not say that she’s all that confident, or believes in herself. She searching for an identity, and freely admits she doesn’t understand what’s happening to her. Her running off to save Kylo from Snoke is as brash and reckless as Luke’s attempt to save his friends from Vader’s clutches in TESB, only somehow Luke ends up hanging upside down below a city in the clouds minus one limb praying to be saved, while Rey conveniently escapes in Snoke’s shuttle, and arrives in time to save her friends with an awesome display of the Force.
This is one of my biggest problems with the sequel trilogy. It’s not necessarily Rey’s quick grasp of Jedi techniques or that she’s overpowered. It’s that she (the main protagonist of the movies) is never, ever, ever in trouble. She’s never in a situation in which she needs the help of her friends. She’s never in a situation where the audience worries about her and I think that’s kind of a barrier to the audience really connecting with her.