His boss is an Actual Vampire and he doesn't actually notice it for an embarrassing amount of time. He notices the werewolf and the mage sure, but not the vampire... So it's going to be a die-roll on whether he registers Cheyenne as anything more than a weird blind girl at all.

That said, if you want her to have a rough mannered big brother? He's your man. He can even hug her thanks to being basically anti-magic.