Dunno what do to about my crush

ATM I am an 8th grader (that is almost 15) at a private school with quite few people going to it. For quite a few years now I have found a girl a year older than I am quite attractive, but lately I realized that I like her quite seriously.

The problem here is is that school is ending in around 6 weeks. She can't stay at this school for high school as there won't be a 10th grade due to lack of students. We also have never really talked, as there hasn't been a reason to, but she seems really friendly and an all around great person.

I am pretty sure she does know that I exist, as for some reason I have caught her eye quite often lately, though I am having trouble recognizing if she actually was looking at me (She has dark eyes which she pinches together when looking at something from range so I can't really see that too well.)

Some days we technically could have overlapping routes after school, but I am really scared of coming off creepy, I had an issue with that with a classmate a few years back. She also comes on Facebook quite rarely, but still regularly enough I could catch her there.

Any ideas, tips? I don't want to just let her go and maybe regret it, or ruin it either.