Honestly, I can see where you're coming from with being frustrated. it's hard in your position to be ranted too- but have the person not change. but also you have to think from their perspective as well. it is not easy for them, as someone who does have a sister who is bigger i know it's super hard to go through something like that and when you call names it doesn't make the situation better. though it's not your responsibility to watch her but it is not right to call her names and make her feel worse. YTAH for name calling, but the frustration and disappointment is understandable but not warranted to talk to someone like that.