Quick question about my girlfriend... please help?

My girlfriend and I are away from eachother for the summer due to our hometowns, and our relationship is going just fine... we have been dating since the beginning of the year and the only obstacle right now is the distance between us. However, I'm just a little confused as to why she never texts me.... it seems that I am always the one to contact her whether its me calling or texting her asking how her day went. Its not that I am worried about our relationship... its just that I wonder why she doesnt initiate the conversations.