Speaking as a canon-familiar person, I think you're doing really well with her personality. She's definitely the Nephenee I loved from the games, just gone through a couple events that have affected her realistically. (And, you know, a pony now.)

Voice-wise, rendering her accent that way is a personal choice, and I might not have chosen it myself, but I think you do it well.

Basically what I'm trying to say is that your Nephenee is very close to canon, and I enjoy seeing her around the game.