So sorry this happened to your daughter OP.
It happened to me repeatedly on my commute into work by train in the early 90’s. All smartly suited businessmen reading the Times/FT and me. I rarely got a seat, as they would push forward and dash to the seats so I had to stand for 99% of my commutes. Even though many of us all saw each other every morning, they would all hide behind their papers and ignore me when I fainted. Worst was when I fainted just as we pulled into the last station and they all stepped over me to get off the train. Another time I clipped my head on the wooden arm of a chair (ancient rolling stock, with the old fashioned seats and doors you had to open all along the carriages) and was bleeding quite badly, again no help whatsoever. I had to get off and walk 20 minutes to work, before I could get any help.
It really damaged my faith in people/society.
It took until my mid 40’s for me to be diagnosed with the, cardiac related, reason why I kept passing out as. Sadly, as is far too common, doctors assumed I was just an anxious, weak female, possibly with a bit of low BP and repeatedly dismissed me. I now have a young adult dc who has inherited the condition from me, but is more severely affected. They have been pretty much housebound for a few years, but if they manage to reach a point where they are able to be more independent I will be worried sick when they start going out and about on their own.
Dh travels to and from London, as well as using the underground regularly. He is always telling me how he’s helped someone out when they have been visibly upset or ill and everyone was ignoring them. The other week there was a young teenage girl, a similar age to our dd, crying hysterically on a bench. He was obviously concerned about approaching her, being a middle aged man, so he went and fetched a member of staff, who managed to calm her down and work out she had missed her train, lost her ticket, her phone was dead and she couldn’t call her parents or get home. Dh fetched her a drink and sandwich while the staff member helped her contact her parents. Poor girl had been sat there for hours, panicking, too scared to ask for help and had been ignored by hundreds of men and women.
In my experience these attitudes are nothing new, an awful lot of people prefer not to get involved.