Looking back over Yugiri's dialogue, I'm almost certain that she was predisposed to think that Eorzeans would discriminate against her kind based on prior contact with Garleans. I figure if you're roleplaying a Garlean character who "recently" left the Empire (say, past decade or so) after having been involved in the Othard campaign, you'd know about the Au Ra.
Might also have a chance of knowing they exist if you're a member of a trading/pirate vessel & crew based in Limsa that sails that far east.
Might also have a chance of knowing they exist if you're a member of a trading/pirate vessel & crew based in Limsa that sails that far east.