Throughout SoA Yvette has been fine, no bugs or anything in her romances. I've gotten through all her dialogue and I don't think I've failed on any of the romances, as she's still part of the party.
However now that I've gotten to spellhold I've had one, almost game breaking bug. The portal that requires the 3 gems, sapphire, opal, and ruby. Whenever I go near the area Yvette begins to stutter when I move her, doesn't follow commands, won't attack, and it makes opening chests/looting corpses impossible as the PC keeps trying to speak to Yvette.
Both her and my PC are stuck facing each other, and if I try to quicksave it says that I cannot do it because I'm in dialogue mode. Using my PC to talk to Yvette doesn't do anything, and having Yvette speak to the PC doesn't do anything.