Tim's done a really good job in creating Kiera because her peronsality definitely fits the series theme.
I really like how she's actually a half-breed, and she struggled to come to terms with that, as it made it a little more realistic. I mean, if I found out there was some sort of mutation with me, I wouldn't take it very well either!
I'm glad she chose to follow her heart towards Potter rather than letting the guilt completely consume her and staying with Luke. I think they both suited her but Potter completes her more than anything, and he gives her the excitement she really needs.