Charlie Chan mysteries, thanks to Charlie Chan: The Untold Story of the Honorable Detective and His Rendezvous with American History, by Yunte Huang.
Actually, it may have been because of this article in the New York Times, by Charles McGrath, or this book review, by Richard Schickel. At any rate, she had read about the Yunte Huang book and the delights of Charlie Chan mysteries, so now she wanted to read one.
And found The Black Camel, by Earl Derr Biggers! One book led to another.
Ah, I see she could have found it here, free, part of Project Gutenberg of Australia, but I think she was happy to find it for $5 in hardcover, to hold in her hands.
After she reads it, she might enjoy the film, with Swedish actor (and lush) Warner Oland as Inspector Chan. I was fascinated to read that the Charlie Chan character only became popular in movies after being played by a white actor. Why should that surprise me? It was 1931. What really surprised and delighted me was that the character was played by Asian actors in the first couple films!
And then there was Jackie Chan!