Marjorie Weinman Sharmat had two dreams as a child: to become a detective and to be a writer. By age 8 she had accomplished both, after she and a friend put out their own spy newspaper, The Snooper’s Gazette. Most of its news came from eavesdropping on adults.

It was excellent training for her future career. Ms. Sharmat became one of the nation’s most prolific authors of children’s books, including the popular “Nate the Great” detective series, which has helped generations of children learn how to read — and how to sleuth. (Tip: It often helps to have your dog by your side.)

Ms. Sharmat died at 90 on March 12 in Munster, Ind. Her son Andrew Sharmat said the cause was respiratory failure. She had moved to Indiana from Tucson to be closer to him, he said.