Should I ask her out?

So Im a junior guy and I like a freshman girl. It really isnt that weird because Im young for my grade and she is old for hers (only a year and one half apart). I just dont know what to do. I think if I asked her out on a date, she would say yes. The only problem is that I dont want to get too attached to her if things work out, simply because I will be going to college in a year. That sounds really weird because Im hoping for things to work out....yeah, Im really confused right now. I really like this girl, but should I just let her be? BTW, I dont let go of women very fast and have been known to like them for WAY too long (as in years).