No, it does not. But it happens again and again that US gun-owners assume that their right to carry a weapon or that their permit for a weapon applies to all other nations as well.

Luckily, she was caught. Regardless if the weapon was "forgotten" or not, being a FA and/or a gun owner, this is not to be forgotten. If it happens, then there are consequences to be taken. There are some things a professional/responsible person is not to forget. Forgetting a gun in luggage is one of them. It may kill people - just think about all the cases were a gun accidently was fired because it was still loaded. Now think of that in a fully loaded plane.