She was likely scared <deleted>less, could simply not imagine how to hide the cash. That kind of money means it belonged to someone wealthy, criminal, or both.
Most foreigners could conceal the money and even use it without an unexplained improvement in lifestyle.
The woman who found it probably lacks the basic privacy to even store or hide it long-term.
I would certainly carefully consider my options if the area were covered by cameras or if someone saw me leaving with the box.
The barcoded bricks are also problematic, it would take some doing to convert into clean cash.