First of all, it is good that you like her really much, as long as you can let her go. Whatever you do, don't get oneitis over her. I can tell you that if you show her how much you like her, making her feel special and that you have selected her among other options (other girls, aka preselection), she will at least be flattered.
Gifts are okay as long as you don't mention anything about money, and you don't expect anything back. So don't worry about that. Just give her the gift, and leave it there. We can compare this to buying drinks to girls in a bar - it is okay to buy drinks under one condition - don't mention the cost, and don't expect her to give you any attention. The best way to do this is to start talking to someone else and ignore the girl for a while. Since you have done something for her, it is her turn to do something for you. Let her come to you.
From what you have described she is probably not interested in you other than as a friend. I can only see one reason for this - you have not suggested anything sexual yet. You need to create that vibe. So go ahead and get your mouth dirty!
