Women, can you give me some perspective on my daughter's Facebook behavior?

My daughter is 12, but will be 13 in a few months. All her friends are on facebook, and we decided she could be on if she friended one of us. Guess what? I’m it! Now, I’m not particularly fond of Facebook because it doesn’t really support conversations like we have here. So I check in with her every once in a while.

Now, I know it’s normal, at this age, to show an interest in boys, but, while she discusses this on facebook, she doesn’t seem to bring it home. At least, my wife has never mentioned anything. Perhaps, being a Dad, I’m just having the normal fears about my daughter growing up, and hoping she isn’t hurt.

So, today I checked in, and found her saying something like “but i look sexy!!!!!!” They’re talking about a photo of a group of them. So the other girls are arguing about who is the sexiest. Now, clearly, one component of this is just fun between girls. However, should I be worrying about my daughter seeing herself as a sex object, and thinking that this is an important component of her personality?