If Mariona has picked this exact moment to overcome her mental block, the one time in her life when it might have enabled her to face reality -- but no. She just has some sense that he is about to spring something on her; and so, whatever he asks her to admit is unlikely, she will say is likely instead.
"I'll get there. It was a rule you would have wished for -- that my Merrin would have wished for -- however utterly unlikely it would have been for a whole planet to adopt that rule. It was that point at which I became sure what had happened to you -- to my Merrin -- however uncertain I remain about what may have happened to me."
"The Merrin I knew -- the original Merrin -- did not much enjoy her job. Some of that is my fault, to be certain, for all that I tried to show her its enjoyments and lead her into those. There are some ways in which it is not a very enjoyable job, unless and until you reach [4th-circle]. And while I was sure that my Merrin had the potential to reach that level in due time, and I often told her so, she was less sure of that herself."
"The one thing she enjoyed most in her life was the practice of nonmagical medicine, after all her healing magic except for [Stabilize] had run out, and she needed to go on healing the stream of casualties from where the [fortress] she commanded was fighting off the endless stream of [demons] from the [Worldwound] [dimensional rift]. Merrin was not proud of enjoying that work, I think, but she was proud of her skill in it. Maybe the only thing in her life that she was truly proud of -- though in my own opinion she had a deal more to be justly proud of than that. And I told her so; but that praise, also, she saw as a burden, and wished not to be told such things."
"You remember a life in a fantastically wealthy world, a world fantastically devoid of the magic you saw as a burden to you. A peaceful life, interrupted only by an endless series of nonmagical medical emergencies. And all the world loved and adored you, for solving those medical emergencies rightly; as though you were a [7th-circle] or higher in the world's order, even as nobody ever made a fuss over that or told you that you were special for it. You had not only me, but many other men; and all of us only ever hurt you in the ways you found most enjoyable, and there was never a good reason to hurt you any more than that."
"It would have been my Merrin's dream."
"It would have been very exactly my Merrin's dream."