Otome Sensou

From MangaHelpers: The story begins in 1420, right as what would be known as the Bohemian War began. A young girl named Sharka is raped and left for dead among the corpses of her whole town, but she manages to survive. She is picked up by the Bohemian forces, who put a gun in her hands and take her on board as a soldier. Will Sharka be able to fight and take her vengeance?