Twilight series again. Appropriate for 11 year olds?

Rachael has been bugging me to let her read Twilight. It doesn't have cuss words, and is pretty tame.

But I am not sure it is appropriate. It kind of paints a very vivid picture of extreme infatuation. Kind of like those first feelings you get with a first boyfriend? Only stronger. Possibly too vivid.

And it doesn't really fit our standards. I would rather my children not think it is O.K to spend the night with a guy, even if "nothing bad" happens. And she does kind of ask him about sex. And you kind of get the feeling they may be "doing it" if it weren't dangerous. I have a sister who doesn't even think the series is appropriate for adults. So what do you think? O.K for 11 year olds? Or not? Hmmm....