What should i do? she likes me too much?

a girl likes me and i like her back. shes 13 and im 15. she wants to wait until she finishes her first year of high school which she is going to this september before we become bf and gf. then she told me she thinks she should stop liking me b/c i affect her too much. like whatever i do affects her mind she says. and she doesnt want to get drive. what does that mean. drive? she seemed sad after sayin that. we started out friends and i really like her. when im with her it feels really natural. we talk everynite. i've nvr really had a gf before and i dont understand whats going on!! this was on AIM btw