Ok, well youve already made great progress, your already friendly with her, and you both have fun, meaning the connection exsists. However your in the hardest part of the process, the friend hurdle. Now your not in a bad place yet, my personal advice is 1st off, try ur hardest to bond emotionally, help her with her problems, comfort her when shes sad, etc;, however you have to be careful not to do this to much, if you act to quickly youll either scare her off, or shell only ever rely on you as a friend, any love hopefuls bad dream. 2nd, try to single her out, have friend interactions, but try to have 1on1 time, like after school ask her if she wants to accompony you shopping, to a small "fast" food joint, w/e, and get to know her more like that (again, dont be to fast/aggressive).
More will come, but I need a typing break ^^;, I hope what Ive said so far is helpful =3