She may just like spending a lot of time with you. The more she desires your company the more you are winning her over little by little. One good way to know for sure just how compatible you are is to go on a trip together to somewhere distant. In a travel situation people tend to reveal a lot about themselves in little ways such as when you share a bedroom together, what food is ordered, or if a situation is stressful than how does she respond to it. Some relationships often are jump started the closer people are to each other. If a romance still is not possible even while in that kind of intimacy than maybe its just best that you remain close friends.