Tldr Cute girl is confusingly shy.

Went to Prom with a girl who I have been friends with for several years. Logistically unable to get jazzy with it after because my friends and I + our dates all went to his house and his parents were hawks. I like this girl and want to get out of a platonic friendship, but she is SO hard to read. She is one of the smartest girls I know, but she is also very shy/introverted/awkward. I can't tell if she is awkward around me because she likes me and would like to escalate, or she is awkward and uncomfortable around me but tries to be nice. She managed eye contact for about 5 seconds during the slow dance at Prom. I also snapchat her sometimes, but she only responds 2/3 times despite having a score of like 80,000 (she obviously uses it frequently with friends). Also hard to tell if she is nervous about snapchatting me or would prefer I buzz off. Occasional immediate response other times just read. Anything flirty is returned with a neutral response.