It feels impossible to recover with my family

Usually I enjoy eating with others because it takes my focus away from the fact that I’m eating and allows me to enjoy and converse with others, but this previous weekend I spent time with my mom and my sister. Whenever we go out to eat or even simply having meals my sister has a disordered eating style and it makes me feel like I’ll never recover. It’s not even her fault, I know that I have to beat past caring about how much others are eating and focusing on myself and what my body needs. But seeing her eat fairly nothing all day, then claim she’s “starving” only to barely touch her meal and eat like a small portion of it. This entire weekend we probably ate our 1-2x times per night and the way both my mom and sister would only have breakfast, and then the next we ate was dinner and they’d claim how they were so hungry, only to not even touch their plate and take it to go and then not even eat their leftovers and order more food the next day only to barely touch their plates again. Just the waste of food by itself bothers me but especially barely eating, it just discourages me with the idea of being able to eat enough for myself and I feel so guilty if I eat more, and being the only one to finish my entire meal.