I am not a doctor. I just wanted to share another perspective, and say please be careful not to only assume this could be an eating disorder. (This post is not seeking medical advice - I have a great team of doctors and not looking for advice.) I also had terrible weight loss, though it was due to early satiety. In my case, many of my providers, including my GI doc unfortunately as well as my dietician, did assume it was an eating disorder. This went on for almost 2 years as a result, until my bowel was so impacted I couldn't even get down water and had to seek emergency services. Turns out I have pelvic floor dysfunction which had been leading to constipation, which was causing my early satiety and weight loss. A steady regiment of miralax and stool softeners is now helping me have regular bowel movements and I can eat again.
I just wanted to say, I think it's very good you're looking out for your patient, they are lucky to have a doctor who cares so much. But please make sure to consider all angles, and not assume it's an eating disorder if something else could be going on. This is not a complaint against doctors by the way, I have tremendous respect for you guys. I just wanted to share this. I think sometimes women weight loss problems get written off as eating disorders. But I could be biased from my own experience.