In regard to Jace and Isabelle... I think that she was getting over a crush on him at the beginning of CoB. But I think that involvement with her and Sebastian is incredibly intriguing... hmmmm.
As far as her personality, I like her. She's vain, undoubtedly true. But she also cares deeply for her friends and family. She is the embodiment of kick-assedness. And great for feminism in the book, because Jocelyn is unconscious, Mrs. Lightwood is not portrayed as a particularly strong or likeable character, and Clary is fairly useless in a fight (other than her runes, which can only be used on very rare occasions).

I like her a lot. She's very...inspiring when it comes to clothes xd

Izzy does seem really girly and bitchy but I'm glad that she's atleast got a brain (so she's no bimbo) and she hasn't got bleach blonde hair. I find it hard to dislike her cause she's determined.

I actually like her.At first I didnt because she was so girly and Im a tomboy.hee hee but now I think shes pretty awesome I dont know how the change happened. Im new by the way.**blushes**

I guess she can be rude.....but at times who isn't? I like her character, she reminds of my sister.

I don't know if I'm right or not, but didn't Izzy ay that Jace was sexy in COB?

yeah she did...why?

Because they were wondering if she liked Jace and I thought she did but I'm not sure.

Oh

well, no, she didn't. As much as a girl can not like jace lol

I had a passionate hate for Isabelle to begin with - she just seem so cruel - but then when she met Simon I found her to be different and i started to warm to her
she reminds me of one of my friends so i suppose thats why i eventually began to like her lol