This Is Screwed Up, But I Was Reincarnated as a Girl in Another World! (Manga) Vol. 12 (manga)

Ren has successfully fended off the guild staffer who was trying to force her to work for free. Using her knowledge of Earth's modern business world, she even creates a new set of reforms to squeeze incompetent kids from aristocratic families out of the guild! Then, Ren’s orphan friends rent a ramshackle home to live in. Unable to stand by idly, Ren decides it’s time for a gut job and a remodel! Is there anything Ren can't do?! She might even change the world!