What should i do? Any advice plzz!?

Well ok there's a problem. My best friend for life told me that she likes more than friends (I'm a guy she's a girl) and I always liked her more than friends and I never knew that she liked me and a while back I dated one of her good friends. She actually hooked us up and she told me 2 days ago that she didn't know that I liked her and stuff me and her txt 24/7 she txts me first thing in the morning. (this Is gonna be really long) I told her that I was going to England after high school and Im goin to brazil nxt summer for soccer things. When I told her that, she was really moody like sad and I told her not to worry that I'll call her whenever I can and skype all the time and she was like I better not get married in brazil and I said naahh I can't do that cuz what if I wanted to marry her:) and she said shell def. Give me permission:) that made both our days. Idk if she's ready for a relationship cuz I think she's still heartbroken from her last bf and she doesn't seem to me that shes ready but I could be wrong too! U nvr know! Right? So what should I do? I wanna know if she wants a relationship wit me! How can I make sure she wants me w/o being creepy or I don't wanna wait too long. How should I ask her out and make sure she wants to date me before asking her. Somebody HELP! And dont just say ask her friend or something cuz honestly I don't think that's a great idea. I really care for her too so how can I show? I give Best answer too thanks guys:)