So first off, I'm 5'6'' and 114-118 pounds. Automatically I'm pretty sure that'll make me look like a condescending asshole. She's always been real pissed about weight around me and used to always call me anorexic and claim that I never eat. I really don't think she wants to hear shit from me. She's about the same height and claims her goal is to hit 130 pounds since she started seriously trying to lose weight. My family isn't very close. There are 5 kids. The other three have moved away and I will be leaving for school in a few months. So I don't have much of an interest in helping her on her weight loss journey or supporting her much at accomplishing her goal. I know I prolly sound like a dick but it's always just been a free-for-all here. We're used to getting shit done ourselves.
Anyways, the whole bulimia thing has been working out for her and she has been losing a lot of weight. Am I obligated to do anything about this? I've thought about telling the sister she's friends with, our eldest, but she is also pretty chubby and gaining weight lately herself. So I can't see her properly helping our youngest sister with her weight problems. I just sort of wanna hear what some strangers think about it since I can't justify telling any family members. Most will probably just make a big deal out of it or encourage her to continue to just be overweight and eat everything she wants. Should I just let her get over the phase herself? Should I mention it to her? Should I tell someone else and have them deal with it? Your opinions please.