> SD-based models can generate child bodies just fine, based on lots of training with non-porn images.

I have not stated anything contrary.

> The generalization abilities of models are good enough in other contexts that its plausible that realistic nude children could be generated by a model with no nude children in its training data that was otherwise trained on both clothed children and nude adults. I have no plans on testing this, however.

Stable Diffusion has failed me for much simpler interpolations than the one you're describing. I don't believe this would work based on previous interpolations I have seen in Stable Diffusion. You can convince me by showing an example, but not by stating that it is possible without one.