That's not a Katana in her hands, but a wakizashi, the 17" long knife carried at the waist along with the Dai Katana, or Life Sword. Samurai also carried a Tanto, or knife, with a 9" blade when in confined areas, as well as the wakizashi, as the katana was unwieldy in small spaces, and so unsuited to indoor wear.
That's not a Katana in her hands, but a wakizashi, the 17" long knife carried at the waist along with the Dai Katana, or Life Sword. Samurai also carried a Tanto, or knife, with a 9" blade when in confined areas, as well as the wakizashi, as the katana was unwieldy in small spaces, and so unsuited to indoor wear.