The Vermilion Koi: The Whole Household's Precious Darling

An orphan from the modern era transmigrates into the body of an abandoned baby in the snow, and is taken in by a duke's household that hasn't had a daughter in a century. The eldest brother has a broken leg, the second brother is disfigured, the grandfather is gravely ill, and the family business is on the verge of collapse. Everyone thinks they've taken in a little bringer of bad luck. Little do they know, the first thing the baby says is, "The bird says there's a flower on the hill behind the house that can save Grandpa." From then on, the whole household kneels to spoil her, enemy troops flee on their knees, and her biological father, the regent, begs her to come home on his knees!