Garlean nobility tend to have posh British accents in this game, and as someone raised in such a household, Ivonne should have that as well. But as a covert operative who has spent years in Doma pre-ARR and Eorzea during her WoL journey, so she would be able to mask her accent well.
#Wolquestion #WolQuoted is your WoLs accent British? Like the rest of the scions?