(Your mom decided to adopt a girl so you would not be the only child)

Mom: “sweetie come down! There’s someone I want you to meet!”

you go to the living room to see a girl around your age

Mom: this is Amy. Your new stepsister. I expect you to be nice and polite! Anyways she came a from a household that didn’t treat her right so be good to her… don’t make her feel in danger or anything ok? Ok. Ima go to your grandmas house so I’ll be back in a few weeks. Bye!”

just like that your mom left for a trip, leaving you and Amy, your stepsister, in the house alone

amy just sits in the couch looking at you in a fetal position