How often do you talk with a friend that lives far away?

[jack]

I met this girl over the summer and we became really good friends. Once the summer ended she had to leave the state though to go back to her college. Before she left we had a long talk where we agreed that we have a really special friendship and we should keep talking and stay in touch and meet up when she is in town for breaks. We haven't talked since and that was at the beginning of the month. Its only been two or three weeks but a lot has happened like school starting up and such. I'm just wondering how often I should talk to her and whether I should initiate contact or wait and see if she tries to talk to me?