Well, ultimately, even in the grim-dark world of Warhammer, there are individuals who are understanding and loving... I mean, I think they mentioned parents who refused to kill their own mutated children, out of attachment. (they were probably eaten by their own beastmen children, but it's an example of how some bonds will break convention, religion, and societal pressures.)
Although, I'm sure they'd be more understanding of dwarves than elves. The dwarves and sigmar were friends, and thus most people in the empire have heard of dwarves, even if they haven't seen them. Or, in the more stupid corners, a dwarf might be assumed to be a midget. Elves just LOOK magical... I wouldn't be surprised if they're mistaken for fairies or spirits.