How do I get out of the friend zone?

I got this girls number a few months ago and we were texting a lot, mostly her texting me first, and met up in town quite a few times too. I asked her out about 3 weeks ago but she said it was a bad time because of exams which are now over. Since then we've still been texting and she apparantly considers me a good friend, how do i make herr think of me as more tgan just a friend without having to ask her out again?