C. Campbell (Colin Campbell) Brown

Project Gutenberg lists C. Campbell Brown, identified as Colin Campbell Brown, as the author of Children of China. Open Library also has an author entry under the same name, which helps confirm the attribution.

Beyond that, reliable biographical details are hard to verify from the sources I could find. No well-supported mainstream reference page turned up in this search, so it seems safest to describe Brown as an obscure author whose reputation now rests mainly on this surviving work.

That scarcity of background can be part of the appeal: listeners are meeting a voice from another time with very little modern framing around it, and the book itself becomes the best introduction to the author.