I’ve seen your update - that will be massively reassuring for her
I have a dreadful fear of travel. I know how illogical it is.
One recent occasion was a boat trip (small boat) across sea that we knew would be rough. I went into major panic mode - wanted to go home. Full on strop (at the age of 45), threatened to divorce my husband etc. A couple could clearly see my distress and offered my some of their travel tablets (sedative effect).
To cut a long story short, I was one of only a handful of people who managed to stay smiling and not sick during a crossing from hell.
If I were in your shoes, I would try to talk to my daughter about the positives of the destination. Do not minimise the fear of the flight. I used to work at an airport and have been talked through the whole process so many times - it makes no difference!
I would instead offer something (like a sedative) that will alleviate the anxiety sufficiently and make the flight bearable. I would be very open about what I was offering as that is reassuring.
To this day, I do not know if i was offered a placaebo or not - regardless it allowed me to feel a little more in control.
I wish I could help more - I understand how your daughter feels. Anger and demands will not help. It’s a phobia and it has no real logic attached to it.
Good luck and I genuinely hope you all get to go. Ps. A really good book/magazine helps me to stay calm and (in my experience) do not try and engage in conversation during the flight.