As much as people in Internet relationships want to believe that they "real" - they are not. Chatting, email and talking on the phone is not the same as being with someone in person, going out with them, actually being in their "real" life. I have been in a long distance and thereforeeee Internet based relationship for over two years and I can assure you that having an online relationship and being with someone for real is not the same thing. Being devoid of physical contact, spending time with and actually being around that person is all so important in a relationship, if such a relationship is to be considered as real and taken seriously.
I agree that perhaps the trust and emotional elements might be satisfied, but there is so much more to be being with someone than those things. Actually being physically with someone is so important if the relationship is to flourish, grow and progress. For the longest time, I felt similar to how you feel - you think you love her and shes amazing - even though you haven't actually met her yet.
Gilgamesh is totally correct when he says that you should meet her as soon as possible. My honest advice is not to even treat her as your girlfriend until you've met her, in fact until you've met her and been with physically her a number of times. I'm sorry to say this but online and offline relationships are simply not the same.
I truly wish you the best of luck, that you appreciate each other offline as much as you do online and everything works out. By the way I find it interesting that she is only 4 hours away and you haven't met each other yet? The girl you love is only 4 hours away you haven't met her yet? What are you waiting for?