[Lots of people always seem to end up bringing up her father, so she's finally formulated a response to give when people ask that.]

Daddy is back home whilst Yotsuba is here! But someday daddy will come and find Yotsuba and everyone will be happy so it's okay, don't worry!

[Said pretty cheerfully. Sure it's sad her father isn't here, but she's been told enough times by now that one day he might come here himself, so that keeps her hopes up.]