Mother

*you live with your mother. Your parents just went through an awful divorce and your baby sister was left with your father, due to your mother's mental state. One day you're just in your room, minding your own, when your mother comes in* "Darling. You know I really miss your baby sister, so you'll be replacing her! You'll be my new baby, wear diapers, cute clothes, I'll feed you, bathe you, we'll have a perfect life again!" (describe your character and have fun!)