My dd is in recovery from ED. From what you’re describing, it is very possible your dd isn’t mentally well at all. And this is very serious. Much as your dd is still within normal weight range, she needs urgent intervention due to the rate at which she is losing weight and her calorie intake.
There is a checklist called MEED (medical emergencies in eating disorders) which healthcare providers use. Your dd is red on MEEDS in 2 ways. Firstly, she is losing more than 1kg a week and secondly her intake is less than 500 calories. The vomiting is also not a good sign. It signifies she’s having some big feelings, probably guilt, after eating.
Idk if the vomiting has genuinely stopped and if she has now chosen to not eat in the first place, ie to restrict, rather than to eat, perhaps what we would consider to be a normal amount of food, then vomit. It also sounds as though she has some level of body dysmorphia as she believes herself to be overweight when she isn’t. And you don’t need body dysmorphia to have an ED, but it is another indicator.
With the rate of weight loss and low intake, you should be getting medical observations for your dd. Heart rate, bp, pulse, blood tests. And it sounds as if she has been restricting for some time, so she definitely needs to be seen sooner rather than later. Because she’s eating so little, the advice should be to take her to A&E today for these. I do appreciate the environment could be very difficult for your dd as she has SEN. And if you choose not to, she needs to be seen by the GP tomorrow for basic obs and an urgent referral to CAMHS ED services.
In the meantime, try and get her to eat at least 500 calories today. Don’t beg. Don’t talk to your dd about calories, the correct words are intake / energy intake. And stay with her / monitor her for half an hour after she’s eaten to ensure she isn’t purging.
All exercise needs to stop at this level of intake, she is going to have bounds of energy right now, until she suddenly won’t. This is all evolutionary and the desire to exercise becomes a compulsion into people, who are genetically predisposed once their intake is reduced. People lose that as they start to restore weight.
As your dd has AuDHD, it is very common to eat the same foods repeatedly. That brings comfort and predictability, so I wouldn’t be concerned with that. Right now, it’s important for her to eat. Did she become vegetarian recently btw? And what do you mean about her always having difficulty around eating / food?
And I see that there’s a post just appeared above mine from Savvysix. ADHD meds absolutely can interfere with appetite and these will not be good for your dd.