It all has to do with resistance. If she has some sort of skin compromise like a open cut or skin lesion of some sort it is possible.
Use a 9 volt battery for an example. touch a 9 vdc battery to your finger, nothing, touch that same 9 volt battery to your tongue and you get shocked, that's because your tongue has a lot less resistance than your skin has.
I tricked my kids into doing that
It was hilarious
I though everyone knew
