I think if James had a good reason to know her, he'd adore her, butttt I can't think of a reason. Now that he's outed as Order with her brother however, maybe they could meet! Once he's gotten out of that pesky jail situation, that is. :P
Antonin is disgusted by her, simply because she's Fabian's sister, but probably also because he thinks of her as a commoner popping out babies because she has nothing better to do with her time. :P He's a jerk, what can I say?