Does this girl like me? Should I keep trying to hook up with her?

At school this year she showed all the signs: she is a bit of a free spirit, but she would hug me whenever she got the chance, and, when we were alone we would hold hands and she even played with my hair once. But during the summer, when we had more time to hang out she takes extra time to answer my messages about hanging out, sometimes seems enthusiastic and other times doesn’t, and (we live pretty far away so this all takes coordination) doesn’t want to put a lot of effort into seeing me. She’s said she isn’t really busy either. I think she really liked me at school; what’s going on? Should I continue to try to get her?