Little Miss Marvelous (One Direction FanFic)

When Mrs. Malik enlists the help of the boys to watch over a friend's (more like super star director) baby girl for some time, they expected an actually baby girl and not a sassy, independent, smart, clever, cunning, deceiving, blackmailing American eleven year old. Realizing she's more than a sassy little girl, she comes to be the playful, adorable little sister they love. How long will big brothers' love last for this little sweetheart?