Since I have known something similar happen before, I can't help thinking that the girl may just have been very naive/ clueless, and has been duped.
Many years ago when I was working for an airline, we flew regularly to an African country where life was being made difficult for Asian citizens generally, and it was impossible for them (legally) to get their money out of the country.
A fellow employee who was extremely sweet but terribly naive, was befriended on one such trip by an Asian couple, who were very nice to her, before asking her more than once to take a parcel to post to their son in Switzerland. Which she did quite happily.
We tried to explain to her that there was almost certainly hard currency (exchanged on the black market) inside - otherwise why could they not post it themselves? And that she would be in the most dire trouble if she got caught - she'd be in jail, the whole aircraft very likely impounded - they would never believe that she'd simply been so naive, or that the whole crew were not at it.
She wouldn't have it at all. The couple were just being nice to her out of the goodness of their hearts.
Eventually she was sick and unable to go on a further rostered flight - a mutual friend went instead. Sure enough, the couple contacted this replacement, and asked her to take the usual parcel to post to Switzerland.
She said yes, she'd be happy to - as long as they'd open it and show her what was inside.
And that, thank heaven, was the end of that, but it took those lengths for the girl to believe - finally - that she'd been duped.
Just saying.