Talia is the daughter of arguably Bruce's greatest enemy and the mother of his child, hardly a B-Lister. I already think Nolan himself has addressed the issue of a guy running around in a bat suit, at least he did in "The Dark Knight". A theme of the movie was how Bruce's psyche could endure his ongoing war on crime. I would consider Ivy an A lister, not sure what categorizes her as B list. She may have a difficult gimmick to accept but makes her no less lethal.