It sounds like you haven't watched Avatar, so I want to confirm your suspicion that this character is absolutely being dragged through the mud here. I'd practically recommend watching the first series just for her (if you think it would be up your alley)

Personality, flaws, charm, humor, etc...she has it all. Her special ability is basically that her other senses have developed quite a bit to compensate for the blindness, so she's a real badass at her style of martial arts - and she never has to whine and moan about being blind or being a girl.

Gee...almost like a well-written character that the audience can relate to no matter their situation. Imagine that.