People have been saying that she was dumb to carry so much money with her. But for one, it's for all the member's including the new group so 30k isn't really extravagant if you consider it's for like at least 14 people. And I guess this amount was meant for the whole trip so that's why it's a lot. Although there might have been a rule not to let the other girls keep their own money so that they won't spend when it isn't the time to do so.
It's unfortunate though. And it seems that it might have been a planned robbery since the robber knows exactly who to rob of all the people. If not, it's really just unlucky.