She grew up in Williamsburg, Brooklyn with her mother an extended family, and wrote her first poem for Arbor Day when she was eight years old.

In 1964, she joined Bantam Books where she worked as a copywriter, editor, and copy chief and as an associate director of marketing.

The artwork for the dust jacket of the hardcover release includes a photo of her daughter, Jessica.

In 1992, she joined the book division at Scholastic, leaving in 1995 to pursue writing full-time.

Gilmour's best-known novels are the Clueless series with author Randi Reisfeld.