She's an idiot. My brother (a nurse) sent me this article and said he was surprised that cruise lines even let passengers sail at 24 weeks (he said he doesn't think it should be past 22 weeks, which echos what some of you have said above).
Bottom line - it's on the website. Maybe she didn't read it, but she signed the cruise contract at some point, and the language I believe is in there, along with the fact that fares are non-refundable. She should be happy
DCL refunded her her full fare.
Also...I don't know exactly what her itinerary was, but the article my brother sent me said it was a "Caribbean" itinerary - isn't Zika still a problem there? If so, IMO, she shouldn't have been on that sailing anyway.