Prolific author Marjorie Weinman Sharmat, creator of more than 130 books for children and young adults, and known for her beloved series about pancake-loving boy detective Nate the Great, died on March 12 in Munster, Ind. She was 90.

Sharmat was born on November 12, 1928 in Portland, Me. to Anna (Richardson) and Nathan Weinman, who sold and manufactured dry goods and men’s furnishings and who served as the inspiration for Nate the Great. As an admittedly quiet child, Sharmat recalled in early interviews including one for Cricket in 1975 that she fell in love with reading and the imaginary worlds of fiction very early in childhood. “My earliest ambition was to become a writer or a detective or a lion tamer,” she said. “I began writing when I was eight.” At about that time, she and a friend wrote and distributed their own newspaper called The Snooper’s Gazette, in which they reported news they “obtained by spying on grownups for our detective agency,” she explained. “It achieved a circulation of about four—her parents and mine.”

The writing bug stuck, and with what she called “tremendous encouragement” from both her parents, Sharmat wrote poems, stories, and kept a diary, and sometimes drew illustrations to accompany her texts. Her work appeared in various school magazines and newspapers. She graduated from high school in 1946 and then graduated in 1948 from Westbrook Junior College in Portland, where she studied merchandising as a “practical” counterpart to her writing. Sharmat first entered the working world with a job at a department store and in 1951 she landed a position on the circulation staff at the Yale University Library in New Haven, Conn.

During the early 1950s, Sharmat’s writing began receiving some recognition. “My first commercially published ‘work’ was a national advertising slogan for the W.T. Grant Company for their spring promotion,” she said in a Something About the Author essay. “It consisted of four words. I used to enjoy walking into Grant stores and reading my four words.” Other early publishing successes of that time included a short story for adults and an article about Yale.

In 1957, she married author and investor Mitchell Sharmat with whom she had two sons, Craig and Andrew. As the family settled in New York City and her sons grew, Sharmat turned her hand to children’s books. Her stories were often inspired by the experiences and adventures from her own childhood as well as her boys’. Her first published picture book, Rex (Harper, 1967), tells the tale of a boy who runs away and pretends to be an elderly neighbor’s dog, and incorporates Sharmat’s son Craig’s habit of visiting older neighbors and son Andrew’s pretending to be a dog.

As early reader books and series started to become popular in the late ’60s, Sharmat felt compelled to enter that arena with better quality stories she thought might appeal to children learning to read. In 1972, Nate the Great, illustrated by Marc Simont, was published by Coward, McCann & Geoghegan, kicking off the long-running series that would grow to include titles co-written by her husband and sons, as well as by her sister Rosalind Weinman.

The Nate books have been translated into 24 languages and adapted for the stage as a musical. Nate has been a clue for several New York Times crossword puzzles, appeared with a milk mustache in ad campaigns, and also could be seen on 28 million boxes of Cheerios during a childhood literacy initiative in 2002. On the occasion of Nate the Great’s 30th anniversary, Sharmat told BookPage that from the outset she “wanted to make this book, inspired by my father, easy to read.” Mitchell Sharmat helped to further expand Nate the Great’s world by creating the character of Olivia Sharp, Nate’s cousin and fellow sleuth, and collaborating on a series of books about her with his wife.

In 1975, the Sharmats left New York City and moved to Arizona where Marjorie and Mitchell continued to publish numerous picture books and early reader titles. Marjorie Sharmat changed gears a bit and embarked on a new path writing YA novels, beginning with the novelization of the TV program Square Pegs (Dell, 1982). She wrote Vacation Fever! (Putnam, 1984) and Are We There Yet? (Putnam, 1985) under the pseudonym Wendy Andrews, but those books were reissued by Dell in 1990 using Sharmat’s name. Also in the mid-1980s, she published the eight-volume Sorority Sisters series with Dell.

Beverly Horowitz, senior v-p and publisher at Delacorte Press, worked extensively with Sharmat and shared some recollections: “Marjorie and I go back decades. She lived in Arizona for many years, but she never lost her New England accent. Whenever she called, I’d recognize her voice and she would say, ‘Well, how did you do that? It’s a mystery to me.’ She always said that creating Nate the Great was her childhood wish come true, because as a girl, she wanted to be a writer and a detective. Nate allowed her to be both while maintaining her connection to her beloved family. Nate the Great was named after her father, Nathan; Rosamond was modeled after her sister, Rosalind.”

She was always happy to write a new Nate book, Horowitz said. “She took her time and devoted real care to each mystery, brilliantly but subtly demonstrating to her readers the kind of deductive reasoning used by Sherlock Holmes—and entertaining them in the process. Generations of kids learned to read and to think because of Marjorie and Nate. And don’t forget Sludge! In the tradition of Dragnet, Nate spoke directly to his loyal pet and trusted partner, who was always by his side. In one of the last books Marjorie wrote, Nate tells Sludge that his two favorite words are ‘CASE CLOSED,’ but I know that even with Marjorie gone, Nate’s cases will be opened and read and solved for years to come. Marjorie was Great!”