That's 19 year-old heroine Alicia Melchiott from the Valkyria Chronicles PS3 version. We've seen her wielding a gun like this before. This is nothing out of the ordinary. Let's compare with her anime version.
Hrm. Still Alicia, and she's still brandishing a weapon. Or should that be weapons? We don't want to make mountains out of molehills, and we're happy to get this off our chest. However, something sticks out in the anime version. We'll keep you abreast of any developments on this bumpy issue.
アニメ『戦場のヴァルキュリア』作画が地味にひどい [チラシの裏でゲーム鈍報]