Replying because there are a lot of misconceptions around Anorexia.

People used to think the calorie restriction was the symptom of a mental disorder around food with a deeper cause (assumed to be the mother)

Now the good standard theory is that calorie restriction is the cause, combined with genetic predisposition - which leads to mental illness.

People who carry the Anorexia gene will become mentally ill if they restrict calories. End of story.

If they eat properly, they will recover mentally

Modern treatment for Anorexia focuses 100% on calories. There is no therapy at all.

Obviously reality is more complex and comorbidity is a thing.

But the point being. Your friend probably won’t be helped by therapy. What they need is good FBT treatment or similar at a clinic trained in modern treatments for ED