Wikipedia:Articles for deletion/Katy (series)
A Google Scholar search (Katy Susan Coolidge) quickly reveals one book chapter https://books.google.com/books?hl=en&lr=&id=gWJMOEFNG1AC&oi=fnd&pg=PR7&dq=katy+Susan+Coolidge&ots=MaGJEoIqvi&sig=XDbK_niMG-80px0m7qYmRLLLdfw#v=onepage&q=katy%20Susan%20Coolidge&f=false (as well as the name of the book being an homage) and a paper in a journal https://muse.jhu.edu/article/457753/summary. ''What Katy Did'' is included in ''Masterplots II: Juvenile & Young Adult Fiction Series''. The author is cited in ''Guide to Literary Masters & Their Works'' primarily for this series. Seems to pass  criteria 1 with ease. Best
— User:Barkeep49, 14:59, 23 July 2018 (UTC)
Stance: keep
Cited policy: WP:BKCRIT (Wikipedia:Notability)