Granny enjoy your toastie 😋 my dd is the same, it drives me demented! I would say she's better than she was but she'd never in a million years agree to an ad hoc snack it would have to be a part of her overall meal plan iyswim. Even though she's not technically on a meal plan anymore she's very reluctant to give up these self imposed rules.
Because I think she is autistic (loads of signs since birth) I think a lot of the rigidity around rules is linked to that.
She is better than she was though, for example yesterday she couldn't take the dog on a walk and fit in driving practice with me. When she more unwell nothing would stop her going on that walk but yesterday, although she was conflicted, she decided she wanted the driving practice more.
The downside was she refused her evening snack to compensate 🙄
She did go out with her friends and had a macdonalds and pick a mix though.
I think im similar to the poster who said they considered their dd to have some weird eating habits rather than ED (I'm paraphrasing 😬) Dd eats enough to maintain her weight, she eats a wide range of foods, no fear foods, she doesn't compulsively exercise , she is independent with breakfast and lunch so it's just the 'rules' that are left to tackle now.