Aya actually didn't know that the 'iron' thing applied to Maleficent. Sure, it was that way in every other piece of literature ever but Disney had a way of overlooking this and that. Like the whole Hercules being the son of Zeus and a mortal.

Grinning, she filed that little tidbit away for later and remained silent. Diplomacy, famously, was not her strong suit after all and she was pretty sure Maleficent wouldn't listen to any attempts she herself made to reason.

Literature suggested that bargaining with fairies was a bad idea too, after all.