@Ciel I think it makes more sense with this translation. Yona was basically baiting them into reacting to what she said, this translation makes it clear that she was baiting them, like "oh, so you actually DO know what I'm talking about". The other translation not as much.
@sukaley
It could be due to overwork. Soo wons mother was confined to bed, yet he is up on his feet running a country.
I'm just making this guess since Yona mentioned it directly after he was wondering why it's affecting him so soon.