As Uriah speaks, Valentina is relieved, both in that he doesn't appear angry and in the fact she had already told Keane she wasn't available and kept their relationship within the bounds of the new found chastity Uriah appeared to expect her to keep to.
When he asks the general question her aura flickers with nerves, but, then, thankfully Marchaux provides her with a temporary out. She knows Keane speaks Brythonic, given Andross' antecedents she's confident he does as well (whoever said visions didn't bring any useful insight?) and given Uriah's history she was confident he too, spoke the language.
So she allows herself to move a little, landing a curious gaze on Jean-Jacques before looking to the others. Speaking in Ancient Brythonic she says "Is the Childe quite well? Only, I had conversation with both Lissa and Durham and they do not seem to... have been affected as he has." Her chosing not to name him seems to have been deliberate, so as not to give him any clue she is talking about him.
Looking to Uriah she answers him, seemingly having forgotten she's switched to Ancient Brythonic. "I have some peculiar memories of things I do not think I would have done on other nights Your Highness." Her aura shows embarrassment and discomfort at the memories.