My sister thinks shes huge

my younger sister weighs a stone and a half more than me. and I am 13 and shes 11. she is almost taller than we and her stomach is bigger. I dont think im small im taller than most of my friends at school. I dont understand and shes getting so self confident. its really annoying how big she is because people keep thinking we are twins or shes older!!! AGGH!
help please.
xxx thanks

My younger sister is taller and bigger than me and I got annoyed as well when people thought that she was older... BUT truth be told I'll be happy when I get older cause I will look younger then her... But for as your sis thinking she is huge I would just help her out let her hang out with you every once in a while it will help build her self confidence... Today its all about being small and model like... News flash most models aren't healthy

Maybe she's really huge!

I have to agree with the above poster on this one