“Sometimes You Have to Lie: The Life and Times of Louise Fitzhugh, Renegade Author of Harriet the Spy,” by Leslie Brody (Seal Press), $30. 

The author's name may not be familiar, but her most famous character is: “Harriet the Spy” has been worming her way into grade-schoolers' hearts since her snooping adventures debuted in 1964.

In this new biography, Leslie Brody turns the tables on Harriet's creator, Louise Fitzhugh, who never set out to be a children's author. She refused to go on book tours and maintained a Salinger-like seclusion until her death in 1974.

In fact, Fitzhugh left behind few letters and no diary, prompting Brody to turn to the estate of poet James Merrill of Stonington — one of the few people with whom she regularly corresponded.

When Fitzhugh met Merrill, she was a student at Bard College trying to escape her stultifying hometown of Memphis. She'd already had a one-day marriage with a high school sweetheart and a love affair with a woman.

She hated everything about the South: her father and stepmother, who had lied that her real mother was dead; the social niceties of her upper-class upbringing; and the immorality of the Jim Crow laws.

Merrill, her faculty adviser, already was an acclaimed formalist poet. According to Brody, he saw Bard as a escape from the distractions of New York society.

When the two writers met, sparks flew, but they soon realized they were destined to be friends, not lovers.

Each wrote the other honestly about the other's work, leaving behind a correspondence that reveals Fitzhugh's struggles to become a serious artist — a painter and a playwright. Merrill read her plays and visited her art studio. She trusted his input.

When Fitzhugh made her first foray into children's literature, she already was an accomplished, if not financially successful, painter. She was tired of relying on her inherited wealth.

Almost as a lark, Fitzhugh collaborated with Sandra Scoppettone on “Suzuki Beane,” a satire about a child with the attitude of a beatnik. Fitzhugh drew the pictures and Scoppettone wrote the text. The book was an instant hit when Doubleday published it in 1961.

“Suzuki Beane” greased the wheels when Fitzhugh proposed a book to Harper about a sixth-grader who likes to spy on her friends and neighbors. When classmates get a hold of her notebook, Harriet becomes a pariah. The legendary children's book editor Ursula Nordstrom snapped up the manuscript.

At 34, Fitzhugh unwittingly had been collecting material for “Harriet the Spy” almost her entire life. Although Harriet lives on the Upper East Side of Manhattan, much of her life resembles Fitzhugh's privileged upbringing: Harriet's nanny, Ole Golly, who is really more of a mother; her clueless parents; the private school she attends.

Middle-grade students are still drawn to Harriet because they recognize the powerlessness of childhood. Harriet is a self-directed heroine with a rich inner life.

It is not lost on Brody that the novel's message — that sometimes white lies are necessary to spare others' feelings — would be of great interest to a gay woman in the 1960s.

Although Fitzhugh dressed like a man and frequented gay bars, she recognized the fictions society demanded of her. After her death, her partner, Lois Morehead, was characterized as only the author's good friend.

Fitzhugh is a compelling subject for the same reasons her character Harriet is: She insisted on the truth, was curious about the world, and hated hypocrisy of all kinds.

By keeping her mother away from her for years, Fitzhugh's father doomed his daughter to a lifetime of insecurity and resentment. Although the two reconciled as adults, Fitzhugh had lost precious years of a mother-daughter relationship.

This is a fine biography, written with sensitivity and frankness, worthy of its subject but not cowed by her, either.

Fitzhugh could be temperamental and obstinate. She exaggerated her stepmother's character unfairly, for effect. She could be a difficult domestic partner.

Perhaps James Merrill summed up Fitzhugh best in his ode, read at her funeral after she died of a sudden stroke at age 46: “Just stick to your own story,” he advised his late friend. “Humorous and heartrending and uncouth.”