Keepfaith do you know where your dd sat per centile wise as a baby/young child? It might be in her red book. For example my dd was always on the 75th centile line for weight and height so I needed to aim for over 100% wfh.
87% is a low wfh and means no sport/no PE generally. My dd never went below 90% wfh and at her lowest weight was extremely ill, low bp, heart struggling, periods stopped, always cold etc.
I banned social media, it's toxic and Tik Tok is especially bad.
Curly the lack of support you're getting is shocking, for your ED team to make suggestions without offering any practical solutions to implement them is laughable! It's like telling you to walk to Timbuktu with a blind fold on and no compass. Have you got a social worker for your other dd? I know it's unfair on her but the only thing I can think of is to ask for respite for a couple of weeks for her and to focus entirely on your other dd.
I can't see how you can get over the barriers of weighing food/pre packaged food otherwise.
Nan yay for the advent calendar 👏🏻 we've got a hero's one here and dd has been helping herself to it which is major progress and the first time in 4 years!