I honestly think she just has a crazy fast metabolism and eats whatever she wants and because she doesn’t do much exercise or really move much she never has a huge appetite so gets full very quickly. Joe has a very similar body to Zoe and so do their parents.. she might fully well have an eating disorder but I think that’s not why she’s so thin.
Lol there are pics of her online where she was the same weight as Tanya. She used to be a good size. So she clearly has the same metabolism as everybody else. Suddenly she shed a ton of weight (probably after seeing the pictures!) and coincidentally, people have slipped up showing her just eating a few mouthfuls then tossing good food away. All of the time. She's taken portion control to new heights. I guess she thinks it makes her look rich to order a big pizza to herself then only eat 1 slice. Same way she tossed out over 30 fabulous christmas jumpers one year. She's a wasteful moo.