You've got the right idea.
It's pretty hard to escape the friendzone. Unless, for some crazy reason, you are dead-set on having that girl in particular, the best thing to do is to just move on. In fact, unless you actually want to be friends with this girl (not a BAD idea. Networking is a good thing), I would just stop talking to her all together.
When you in the friendzone, in my mind, there are three different situations:
A. You never tried to be more than a friend. The disadvantage is that she doesn't really think of you as a potential lover. The advantage is, she has probably never put serious thought in to the possibility (I.E., there is a CHANCE that you can instill desire in to her head)
B. YOU put HER in to YOUR friendzone. This one is great, because it really makes you out to be a prize, and from what I've seen is the equivalent of having ***** on call. Bonus points if you flirt with her a little bit now and then just to keep her hopes up. The only real reason to put a woman into a friendzone though is kind of like a big neg hit (I don't think you are good enough for me), or if you really aren't as in to her as you thought. Otherwise, you should be tappin that ass.
C. She put YOU in to HER friendzone. This one applies to the situation being discussed. At this point, she has it in her head that you are not what she wants for a lover. Especially if she keeps talking about having a boyfriend, and especially if she is rejecting your kino. I've seen it happen before. But you've got to make a real impression on her.
My advice is that unless you want this girl as a friend, cut her off. If she has any sort of interest in you, she will try to get ahold of you. Make yourself real unavailable, and with any luck, that will send the message to her that your time is a premium, and you have no intention of spending it being some *****es buddy.