Can a girl go with a guy friend to prom and mean nothing more than friends?

Im going with a really good friend who ive known for a while. We are both seniors and decided to go together. For twin day we wore matching shirts that said i love my hubby and i love my wifey and she and her friends gave ballons and cupcakes for my b-day. However i heard she said she just sees me as a good friend. Does she like me or are we just good friends???