Big hugs to you and your dd Momma! We just went through something similar. We arrived at Disney on Sunday with the intention of doing a "land and sea" vacation. 4 nights at Coronado Springs, 3 nights on the Dream, sailing Thursday.
Tuesday we went to bed only to have our son wake up at 2:30 am vomiting everywhere. The rest of the story is similar to yours, vomiting diarrhea, high fever, stomach pain. He felt better then it came back with a vengeance. Our son is also a Type 1 Diabetic so for him not to be able to keep anything down is super scarey. He needs to eat to take his insulin injections to keep keatones (acids) from building up in his blood, but he needs to ingest sugars to balance the insulin. Not fun. We are also Canadian so very unfamiliar with how the American medical system works(other than you have to actually pay for health services there).
At any rate, we had to cancel our cruise, change our flights and we got him home safely....but what a long frightening few days it was! He is still ill (as is his older brother now), but they are now able to keep fluids down
I just wanted to let you know you are not alone....you absolutely did do the right thing not dragging your poor sick dd to port......I totally understand feeling scared, stranded and helpless because we just went through the same thing. Good luck to you and your sweet dd. I hope she (and you) are feeling better real soon