Nathan Roberts in a visual medium, you can have kids passively present in the narrative, as background figures in a painting or sculpture or photo, or as extras in a film. In an aural medium, you have to either have voices of kids in the background or say explicitly “There are kids everywhere, and here’s what that’s like….”

In role playing, if it’s not actively narrated into the setting, it is exceedingly hard to assume something is there. That assumption could (and has) led to “there were no women who fought” and “there were no people of color in Northern Europe in the Middle Ages” and the like.