The monster duchess and contract princess

As long as she could be loved, she wouldn’t mind being starved or beaten. However, when she was thrown to the fire as a sacrifice for her sister, her hopes were shattered. “Adopt me.” Leslie, who barely survived in the fire, went to the Duchess, who was looking for a little child to adopt as her daughter. “No, because I know you’re the best dark magic user in the empire.” “Leslie, come this way.” “No, yesterday you ate with first brother, so today you should eat with second brother.” “Leslie, I have your favorite jelly here.” My brothers make a contest every morning, asking me to sit next to them. Hey, what is this relationship?