How to tell if this girl likes/wants me? Girl hasn't responded to me. How to tell if this girl is interested.?

After being friends with this girl for like a month. We finally started to be more intimate (kissed, cuddled, slept together multiple times). This went on for about 3 months, then we both had to go home after school until the next semester. We both live in different states but have seen each twice (at school) since going home. I also heard that she has hung out with her ex while being away form me. I haven't heard from her in like 2 months and have kept minimal contact with her by texting but her responses seem like she is uninterested. I've tried meeting up again but to no avail. What should I do? Is she interested in me or should I wait until school starts again?