Is this crush or relationship worth pursuing?

The situation spells out like this: She’s a girl in school I have liked for a year, known her for 6 months, and been talking to her on and off, mostly on Facebook because we don’t have much time other than that. The conversations used to be pretty great, but now they are dying down. She’s getting busier. Every time I do talk to her in person or otherwise, she seems interested, she puts her lip gloss on every time we meet, she holds eye contact. On chat she is also friendly, but doesn’t initiate as much as I do. We still have fun though. She’s busy because she is preparing to leave for college. Her last day of school is in 3 weeks and then she has exams. Honestly I imagine us to be in the perpetual grey zone.

And no I haven’t asked her out, for the life of me I can’t think why. So the question is, should I continue with my interest for her? Should I ask her out (I know this one, yes)? But would it be detrimental on her part? Would she reciprocate? As much as I think she likes me, I would say I like her more than she does me.

What do I do? Critics and romantics on Fluther, help me.