She was on a tourist visa, not a J-1, which is the visa you'd need to be an 'au pair'.
Border officials have wide latitude to ignore things, and for someone like this young lady they were definitely inclined to look the other way as long as they could.
Sadly, she’s collateral damage in a really dumb fued.
I don't see Griner as comparable since it wasn't about immigration, unless you are comparing in the sense of scapegoating.