Should have been released in drabs and dribbles through a cut out third part direct to dealers. The museum will take them because the government will take it all. She’s lucky they don’t tax her for the amount.
In the US if you found a couple hundred gold coins, you would have to consider it “income” and when you sold it, it would be subject to capital gains tax. Of course that’s after everyone else gets their cut.
It’s not even worth walking around with your eyes on the ground.