Hey Helen
It sounds like you had a fab time shopping yesterday. Well done for steering clear of naughties, I couldn't have done the same!
I feel for your sister, it sounds to me like she is in self destruction mode, all that breaded food for dinner and fattening chips too. Maybe all her whinging and moaning is a cover up as to how bad she feels about herself and maybe (dare I say it) she is a teensy bit envious of the fact that you managed to lose weight and left her behind. You say you want to lose more and feel worried about jumping in a swimming cosi for your holiday, but the fact is Helen, you are comfortable in your own skin, your sister isn't and she is probably very aware of that.
I have a very slim friend who always looks great, she told me recently that she has always envied ME! (we have been friends since we were 11) I never got it but she explained that I am happy, a happy confident person and she isn't. She moans to me that her knees are too big (?!?) or her belly is a barrel shape, her nose is too wide, her hair is to wiry - she is never satisfied despite being a size 8! I don't necessarily like the way I can't fit into the clothes I want to, or hate most of the photos I have taken of myself, but I have never let my size stop me from doing anything. I will wear a cosi, I know I wont look good in it, but f ___ it I will wear it and I will have fun in it. You seem to be the same sort of person, you will always be plagued with this food issue (addiction?) like me, but you will always keep trying, because thats who you are. Your sister, at the moment, can't see a way out, another than to keep stuffing her face - which as we all know is not the answer. She will do something when she is ready, or when something happens to her that will stop her from living the way she is currently living, it could be something tiny like a chair giving way from under her or something, a shock. For now though, she is wallowing in her own self pity and that is not a great place to be. I do hope she finds happiness within herself.