For your whole life your mother who is quite fat, has been rather doting on you and your 2 older sisters, with her fattening them up when they reach 18-

You have recently become an 18 year old girl and she has began feeding uou a lot of food and doting on ypu, pampering your, spoiling you. She is very generous and hasn’t allowed you to leave the house.

She enters your room with cake happily