Isn't Suika supposed to be a few centuries old, or at least older than "child"?
I assume the artist means they have the body of a child but mentally she is an adult. That or by oni standards, she is basically a child
AngerEnjoymentBreasts: Essentially none.Eyes: Clear and strong, like you'd expect from an OniLegs: Thin but compact.Butt: No meat here yet.SorrowHair: Silky and expansive. If you're drawing her bangs, be sure to keep the cross-section in mind.Joy.Height: Still a kid. (Around 4'5'' to 4'6''.Waist: Seems like it'd be muscular.Expressions: A heretic among the oni because she hides lies and weakness behind a mask. Physique: She may be a child but being an oni means she's still quite toned. Probably has more power than she knows what to do with.Omake: Should probably be a loincloth, but canonically she wears bloomers, so I end up picturing that. Doesn't wear a chest wrap or bra. Probably doesn't need one anyway.