Her name is Alice(Arisu) Shimada. She's one of the new characters in the Girls und Panzer der Film.
EDIT: To the one editing the info, Where did you get the surname "Kotobuki" for Alice? In the official merchandise it's Alice Shimada and not Kotobuki. If you want proof, here's a translated movie character info: http://i.imgur.com/7vh5r3W.jpg WARNING: Spoilers Alert, look at your own risk