IS SHE REALLY WILLING TO GO ON THIS DATE WITH ME?

i don't know what she's thinking or what she's trying to say. it might be some sort of test though, and if she sees that her sister and you get along well and you're not rude to the sister, she might like you more...and if the sister approves of you, she could actually be an advantage. being a little sister myself, i could also understand the urge to meet you, her older sister's prom date. just let her bring the sister along, and make the most of it! good luck (: