Childermass has no idea whether Norrell may actually be able to banish someone from the realm, but he supposes he's not about to question it. Not in front of a woman who it'd be beneficial to fear them rather than question them.

He leaves the talking up to Norrell himself, instead attempting to take the moment and the advantage of their distraction to assess her. Fae, she is. Fae, and not happy with their efforts. And why would she be, he supposes, considering everything. Childermass glances at Norrell and tries to do his best to convey the idea that he not do anything rash before he turns back to their opponent, preparing himself for whatever she has for them next.