Do you have any indication that she's the type of girl who messes around with people? If not, I'd say she's honestly interested in you. My husband and I had a relationship that started electronically like that. I considered him my best friend before we got romantically involved. After we became best friends, I realized I wanted more and started flirting with him. I tried to hold off on saying I wanted to be with him when we were chatting on-line because I thought that should be saved for when we saw each other in person. The same thing is likely happening here.
The only thing you need to watch out for is that spending time in person can be different from spending time chatting on the computer. You should wait and see how things go when you spend time in person. There's no secret to making it work or winning her over. The best thing you can do is just try to relax, have fun, and be yourself. If the two of you are compatible, it will work out.
Good luck!
“This planet has - or rather had - a problem, which was this: most of the people living on it were unhappy for pretty much of the time. Many solutions were suggested for this problem, but most of these were largely concerned with the movement of small green pieces of paper, which was odd because on the whole it wasn't the small green pieces of paper that were unhappy.” ― Douglas Adams, The Hitchhiker's Guide to the Galaxy