What do you think of this girl?

I think what you need to do is do something so she realizes she can't live without you. Treat her well, make her feel special, ask her what she wants, ya know, take her out, just treat her like a princess. I had this issue as well when I first started dating, and i will be the first to admit, my gf is the biggest flirt ever, but if you make her feel loved and appreciated it will go a long way. If you are going out of your way to do that, and nothing is getting any better, then you will have to face the cold hard truth that you need to move on. Or at least tell her that, and see what her reaction is. Hope this helped.