Irabeth has long experience in staying calm, remaining civil, and bearing undeserved insults. Her father was lauded as a man of saintly good temperament (you know, for an orc); she herself was sometimes complimented on being a paladin, the 'despite' hanging loud and clear in the air. A raving cultist is so much water off her back. She just hopes Cherry is the right kind of person to be impressed by her civilized demeanor, instead of being swayed by emotion.
Despite the stakes she feels - at peace. This is where she belongs; this is what she is meant to do. Perhaps the Inheritor made her wiser, she marvels, the better to carry out her new task.
"The world contains great evils not of our making. We Iomedaeans work to fix it, as best we can, and sometimes this means accepting a lesser evil, or even causing one for, yes, the greater good, because we are not all-powerful, and we must choose our battles. We don't make anything worse - not knowingly, not deliberately - by our presence. All the evil you see exists despite us, not because of us."
"A paladin queen rules Mendev, and yet Mendev is a horrible place to live. This is the demons' fault, not Queen Galfrey's. Any achievable alternative to her rule would be far worse."
"I know this not because I am an expert on Mendevian politics, but because that is what Good is. If the Queen thought it better for Mendev for her to abdicate, or if the Goddess thought it, she would be gone without a second's thought. I know that, because I know she is a paladin."
"Iomedae's place, within Lawful Good, is to be the General of Heaven. Being a general means allocating resources, making painful choices, leaving some people unrescued and letting some of your men perish so that the others might live. We do not see what She does, we cannot always make sense of Her actions, and She cannot afford to explain them to us. But we know She is wiser than us, and better, and we have faith that if She orders us to die it is in a worthy cause."