Yfandes doesn't answer in Mindspeech, she can't answer, but she does try to hold up what she's thinking and not quite able to articulate for Bella and Vanyel to see.
In reality, Yfandes thinks that–
–that Vanyel is her Chosen and she made a promise to him; whatever we do, we do it together; and a Yfandes is a pattern that can't walk away;
–that Vanyel looks at Leareth, an immortal (wrong-bad-no) mage who looks at the gods' work and finds it wanting, and her Chosen wants to think (wrong-bad-NO) about whether he's right;
–that Vanyel, her Chosen, hers, agrees at the very least that the gods never had a monopoly on the meaning of right and wrong;
(WRONG-BAD-NO)
But the scream is muffled, barely tolerable, and she can just. keep. staring. at that awful desperate contradiction, because Vanyel needs her and she can't but that doesn't matter, failing him is unacceptable, so she's going to keep asking herself the same stupid goddamned question over and over and over–
...
Until the answer starts to change.