Hey Guys, I'm from Germany and fairly new to the scene. Because I'm abroad right now i am not able to get the necessary books right now

So basically I really like this girl and would love a relationship or just a physical one with her. I know her pretty well and we get along very well and there sometimes is sexual tension, we openly talk about sex and stuff like that. Until now i was more in the friends zone, we slept in the same bed more than once and nothing happened. But right now I am, as I said abroad, and she tried to call me, so I texted her that I'm still away and she texted back, that "thats sad, because she just broke up with her boyfriend and she wanted to party with me ". I texted her back, that "I'm sorry" (which I, of course, am not) and "if she wants to talk she can get on the internet, because those sms abroad are pretty damn expensive". Now she didn't answer that one and I don't know how to proceed with her.
You have to know that if you told me about all this stuff I read on the site about two months ago I would have said "yeah right!" but she really seems be this sport, that you can only conquer with game.
Now I don't know what behaviour is best, I'm afraid I would lose her, if I'd stop showing this interest in her, but on the other hand she could be a bit more interested in me.
I'd greatly appreciate it if you could give me tips on how to proceed with her, if you need more info feel free to ask.

Blakey