I had an infant who wouldn’t feed @YTT ..... the ENT specialist recommended that I up the energy level in what food she would take in, by adding a little butter, cream, protein powder, etc. Technically your daughter is still a child, so perhaps you could try this with her on the sly.... even a little “extra” may help to hold her until a proper solution is forthcoming .... and it can help you not feel so useless in battling this thing.
I remember once a few years ago my mr. throwing tantrums the night before we were due to fly out somewhere, because he had to make his own Spinach slice to take with us .... boxes of it .... but the pastry he was trying to use was only rye flour and water, and he was trying to roll it very, very thin .... and it kept breaking.
My MIL was there. She tried rolling it out .... it broke ..... Mr. threw his hands in the air and stomped off to the bathroom for a moment. I picked up a bottle of olive oil and tipped 1T into the pastry mix in front of my MIL, and kneaded it in ..... then quickly rolled it out to the thinness he wanted ..... and we all got to go to bed for some sleep before the morning flight .....
Don’t know whether MIL ever told him, or whether she had enough sense on this occasion to hold her tongue ..... cos if he knew the oil was in it, he wouldn’t have eaten it .... and because it was enough for the week, and there was precious little else he would eat .... the trip would have been a complete nightmare that might have involved trying to make more in the hotel room and insisting the hotel cook it all ..... I kid you not .....
We have progressed .... he now eats spinach slice with oil in the pastry and not made from rye flour ..... 🎉🎉🎉
I hope this helps. Keep swimming ..... 🐠🐠🐠