I think that either she was 100% in on it, or that without knowing the details, the hammy acting and 'little Kane on the quad bike, go get the chequebook, honey' thing made her fairly certain a 'prank' was about to take place.
But only an utter idiot would set up the fake death of a three year old for self-publicity purposes and think it was funny. Did the Aylan Kurdi photo not make it to FuckwitLand? Or the footage of Syrian hospitals stuffed full of actual shelled small children?