While I'm sorry this happend to your daughter, I'd like to point out that you, OP, are most likely right about one thing, which is that your daughters party didnt had all the information they needed to handle the situation better.
I could be wrong with my guess here, but... did your daughter let the party know that it was her first time in that trial and that she was very nervous about it? In my personal experience it goes a long way to just type a little message in partychat, letting everyone know that its your first time, stating that you're open for any advice and that you're going to try your best - some people will still be jerks, but with being pro-active like that you stand a good chance to at least win the sympathy of the rest. There is a lot of great advice in this thread already, but I'd like to add setting up a little "Hi, first time here! I'm looking forward to this run and am going to try my best, but if you've got any advice for me it would be appericiated!"-macro thing so that when she enters a duty she can just hit that button to give everyone the information they need (We have a new person) and make a good impression (the new person told us so themself and is open for advice).

...best case scenario is obviously that she doesnt run dungeons/trials totally by herself though to ensure that she always has an ally.