Anorexia and ASC Inpatient for 2 years

Hi I have a question for carers and ASC individuals.  Is it just my beloved high functioning  daughter or has anyone else been in a CAHMS tier 4 inpatient unit for anorexia with little progress?  My daughter has been an inpatient for a total of  2 years, yes 2 years,.  First stint 14 mths, discharged for 4 mths then readmitted in Feb this year and been there ever since.  She has been sectioned since Feb 2017 so unless we try to get it revoked there is little we can do.  She's tried so hard to conquer anorexia but her thought patterns are so rigid.  She currently attends college 3.5 days a week studying Wildlife Conservation (she has so much empathy and compassion for animals ) whilst an inpatient but has to do so with an NG tube down her nose, which makes her difficulties more visible.  She is a safe weight now but without the tube she  would drop weight very quickly even though she does eat a reasonable amount. 

I just wondered if anyone else has similar experience because I'm beginning to despair.  She will be 18 in May and my husband and I are scared what will happen to her when she's transitioned to adult services.  I need a magic wand!  I'm not looking to 'cure'  her autism, I love my quirky daughter just as she is, but do want to cure the anorexia (remission perhaps?).  We need to try something else.  Help!