H. B. Gilmour was a bestselling author of childrens books. She grew up in Williamsburg, Brooklyn with her mother and the extended family and fondly remembered writing her very first poem for Arbor Day when she was just eight years old. As a teenager, she moved to Florida to live with her father. She attended college there and then moved back to New York City.

Gilmour’s first publishing job was at E.P. Dutton. In 1964 she joined Bantam Books where she worked as copywriter, editor, and copy chief and as an associate director of marketing. She was married to Bruce Gilmour in 1968. She had a child, Jessica, with him in 1970. They were divorced in 1972. Her first novel The Trade, a trashy paperback about the publishing business, was published in 1969.

She wrote novelizations (including Saturday Night Fever) and childrens books (including Muppets books) while working full-time at Bantam and raising a child on her own. She published her second original novel So Long, Daddy in 1985. The artwork for the dust jacket of the hardcover release includes a photo of her daughter, Jessica. Her third novel was Ask Me If I Care, a book about a teenage girl who gets in with the wrong crowd.

In 1992 she joined the book division at Scholastic, leaving in 1995 to pursue writing full-time. She focused her energy on books for tweens and children which is what gave her the most joy.

She met John Johann, whom she would later marry, in 1992. They later moved to Cornwallville in upstate New York where she happily tended to the garden she never had in the city until her death. She died on June 21, 2009 of pneumonia due to complications from lung cancer. She is survived by her husband John, daughter Jessica, stepchildren Wendy and John, Jr. and step-grandchildren Reef, Riley, John Jr. and Jasmine.