I totally know what you mean. My sister does the same thing and yes she is younger than me. She is 13 now. But I alwayas have to make her food and she doens’t have to take care of her diet on her own like I have always had to do. My mom and dad make her formula in the morning so all she has to do is drink it. and I always have to make her something to eat even if it is something i dont like to eat i have to make it so she gets some. She doesn’t know how to cook or do anything and when I was her age I knew how to do a lot! it is frustrating!