Does she like me and how can I ask her out?

Ok I'm 18 and a senior and she's 15 and a sophomore. We hang out quite frequently. We went to a concert for my birthday (we were just friends then) but we started going to movies and lunch/dinner in about october. I really like her and it took me forever to tell her until I was super high at a friends. But I'm pretty open about it now. We hangout all the time and have texted all day every day since we met 5 months ago. I think we've seen 6 movies and hungout about 14 times total. Do you think she likes me and how to ask her out ASAP. She says stuff she likes about me and likes me but then she calls me her friend. So that's why I'm not sure. I'm open and told her I like her.