Do I have a chance? Does she like me?

To be blunt, don't waste your time. Mini-players and 15 years old, don't go down well. And from that story I don't see a single sign there that she likes you. Don't try interrupt her immature stage - she'll hopefully grow out of it. Just keep being friends with her, but don't become best friends (because then theres next to no chance of her seeing you as anything other than a friend) don't be too in her face, have fun with your other mates, if she likes you believe me she'll act on it. So just be friendly, and see how it goes. Keep an eye out for someone else, she doesn't seem worth it.