Where am I with this girl? I'm lost.?

I'm 14, she's 15. She's like the most popular girl in the whole school, she's really cute, and she's a cheerleader. She talks to me, we hold hands, hug, hangout (at like the movies and stuff.), she says I love you and all that other stuff to. But as a friend. She's my bestfriend. And I'm her bestguyfriend. Ive asked her out before, she said she doesnt want a boyfriend. (She says that to other guys too, its not just me) Shes never had a boyfriend, that i know of. She would tell me. She tells me everything. Shes not a slut, shes really sweet and caring and stuff, unlike other girls. We text and talk on the phone, all the time. She texts me, stuff like, "Good night sweetheart, I love you whiff all my heart<3". In fact, in her phone, my number is saved 'BESTFRIEND!<3' I'm really sensitive, like I am close with my mom and stuff. I also write poetry. I tell her she's beautiful everyday. Theres this other guy too. He's got a girlfriend. I think she has a crush on him. He's a playa, he hugs and kisses like alot of girls. Even if he has a girlfriend. She talks to him, walks with him, and talks ABOUT him. I want to be more than just bestfriends with her, she hugs me and calls me at like 2am and stuff. I really think we could end up together. I know I don't like her just cause she's cute. I know her personally. I may be wrong about her crush on this guy, but I dont know. She looks at his facebook and stuff on her phone. She texts him sometimes. Even if she doesn't end up with me, I hope she finds the right guy for her. The last few weeks have been like a movie. I'm afraid to try much else, because it dont want to kill our friendship. Help? Advise? Thanks.