I haven't read Batman and Robin #1 yet, but apparently, she's related to something that Morrison is setting up with one of his new villains, Professor Pyg, I think.
But from what I can tell, she's meant to be deformed, and it isn't just Quitely's art style. After all, he did a perfectly acceptable job with his version of Lois Lane and Luthor's neice (the name escapes me) on All Star Superman.
Plus, if the Red Hood is the Joker, which is what I believe, what better joke than to have fairly ugly Robin to his Batman, given what a handsome guy the original Robin turned out to be?