Most Helpful Girl
A girl can like 2 or more guys at the same time. It does sound like she likes you. What does she say when she talks about this other guy? Maybe the other guy is her best guy friend, most girls have them. When you say prom, does she asks who your going with, or what your gonna be wearing? Ask her who she hopes to go with/who she's gonna ask.
Take a small step back, text her twice a week, or even once. See if she texts you first.