Sad and tragic... and complicated by the fact that the countries where ships register -- and international laws regarding incidents at sea -- can make it very difficult to get answers.
I'm surprised they had to have a fundraiser to raise the money for a trip to U.S. -- you'd think Disney would assist with something like that. Guess not...
If you go to the Rebecca Coriam website link given above and go the link area in the site, you will notice right up top they include a link to the cruise law news website. There is a reason for that: the site details the deep, dark black hole that most of the scores of passengers and crew who disappear from Bahama registered cruise ships end up in. That's the result of the quick, superficial "investigations" that occur when a ship holds said registration.
How heartbreakingly sad. That poor girl and her family. A ship's registry is something to think about before taking your family on a cruise, no one wants to think that anything bad could happen on vacation but you just never know.
I hope they are able to find some answers and closure.