I'm not quite understanding the timeline of when the nurse was told she could not fly, when she took her temp and when she got on the plane and then when she reported to the hospital. Cornfused here.
Well, I'm going to go out on a limb here and say that a critical care nurse should a)not need to be told not to fly as any nurse with a lick of intelligence understands the need to "self-isolate."
i·so·late
verb
ˈīsəˌlāt/
1.
cause (a person or place) to be or remain alone or apart from others.
"a country that is isolated from the rest of the world"
synonyms: separate, set/keep apart, segregate, detach, cut off, shut away, keep in solitude, quarantine, cloister, seclude, sequester
and b)If I had to guess, she's had this trip to plan her wedding on the books for some time. Somehow, she managed to convince herself that she was not in danger or a danger to anyone else. Convinced herself of this even after she began experiencing symptoms.