There's a basic and driving hypocrisy at the core of the emotional connection we see here. She's most sorry for Gerald when he speaks of a massacre that, by our own knowledge, I believe we could state entirely truthfully that was unnecessary. I suspect this is part of Gerald's discomfort. There are ways to cure the hunger and madness brought by the Illithid. We've done it. It just requires high magic, or the aid of a god that is not of the Seven. The easiest way to break her connection to Lucan from this is to throw the fact that he has committed atrocities that we would not have seen done, because those afflicted were curable.
She believes in mercy, redemption, healing, we have made all of those parts of her stronger. The idea that a supposed paragon and Chosen would abandon that course would not go over well. And given how Gerald is so uncomfortable, I suspect he knows this too. Crakehall was a flashpoint.
And this is just option 1. I have others.