LA's Dietician checkup

Today we took our gorgeous 7 month old daughter to the hospital for a paediatric dietician's appointment. She's been under a dietician since she was 8 weeks old as her can't sustain any weight gain, food is just a mystery to her she has never cried hungry ever!
We started weaning her at 6 months old using a mixture of baby led weaning (blw) and jars or homemade mush
Today we were told that she had lost weight since her last check up 2 months ago and is now back too monthly appointments at least until she is 1!
The dietician said we have to make her special formula more calorific by adding 9 scoops of powder to 7oz of water, and also prescribing her iron drops and multi vitamin drops.
The weaning is not going to plan she will only eat 1 solid meal a day and as also started refusing her formula as well the little monkey!
We have had a bit of success today with the blw she mullered a whole rusk in minutes hopefully that's the start of a healthy weight gain. I am sure she is trying to make certain she's the youngest sibling by causing as much worry as possible!