[To be honest, Yuuki feels somewhat reluctant in the moment. It's not for lack of wanting to be honest, or because she thinks it's somehow amusing to keep the children in the dark. But she has to question how much good it might do in the moment. One of the most difficult things she's experienced is the frustration of being left in the dark.
But that is different from this.
Neither are looking for a past that by rights should be theirs. Neither are they related to the events of her own world. What they have are two children who have been hurt in the past, and she knows that by revealing what they plan to right now, will hurt them more.
The question isn't really about honesty. So much as how right or wrong is it to deceive them, knowing that the children assume them to be human.
While Zero stands, she wonders if it wouldn't be less intimidating for them to sit or be moreso at eye level. Hands folded, she tries to smile reassuringly at them, but isn't sure how they'll take what's to come. At the least... she hopes, that in Zero's case, Yuu will be able to see the connection they share.
Even if she may be what is the most frightening of all.]