[Merlin would definitely be talking to Yuuko, once he's gathered his own observations.]

That she was. [Thanks to Merlin meddling with the circumstances of her birth, though no one but Uther needed to know that.] Not that anyone would've suspected it at first, when she was younger. Even if she was eager to learn, she still got easily tricked during spars. After training, there were times I found her sleeping in the stables, on a haystack in the stall next to her favorite horse.

Even after she drew the Sword of Selection and started winning wars, not everyone was convinced she was the king they needed. Goes to show you how might and magic aren't everything.