Whistlersghost

 Pearl Buck illustrators 

Personally, I am aware of no precedents for including references to illustrators of works in the biography of the author. Such content could reasonably I think be added to the content in the bio of the illustrator, but from what little I know the author doesn't necessarily choose the illustrator, so there's not necessarily any real connection between the author per se and the illustrator. Having said all that, inclusion of such info in the articles on the books themselves makes perfect sense, and if it can be established that there was a degree of personal contact between an author and an illustrator, that could be referenced in the article too. But personally I can't see justifying the existing section in the article in question. I'll make similar contents on the talk page if you so request, but I'm kinda new to the biography project so I can't cite previous cases as well as I might like.