Jeffries lived a normal childhood until she was seven, when her parents became missionaries and moved the family to Thailand. Over the next eleven years, Jeffries had many adventures, including being chased by a baby elephant, playing in a rain forest, and experiencing the entire series of rabies shots. Because she only had her siblings to play with, Jeffries escaped into the world of books, reading everything from comic books to classics, with romance novels being her favorites. She began making up her own stories when she was twelve, only to discover that every one of them was a romance of some sort.
Jeffries earned a Ph.D. in English, writing her dissertation on James Joyce. While serving as a visiting assistant professor of English at Tulane University, Jeffries attempted to develop an academic work from her dissertation. Bored with this attempt, she began writing a romance novel instead. After realizing that she enjoyed writing more than teaching, Jeffries left the academic world to work as a technical writer, while writing novels at night. Although her first attempt did not sell, after ten rejections Jeffries's second book was finally picked up by Leisure. She has since sold thirty-one novels. She has published historical romances as both Sabrina Jeffries and Deborah Martin, and contemporary paranormal romantic suspense as Deborah Nicholas. Jeffries has won the Holt Medallion Award, the Maggie, and the Booksellers' Best Award and her novels often place high on the USAToday Bestseller's list. Her novels Beware a Scot's Revenge and Let Sleeping Rogues Lie became New York Times Bestsellers.
Jeffries writes in her home office. She also participates in a group blog called The Goddess Blogs. Because her family's schedules fluctuate, however, she sometimes does not sit down to write until the middle of the night. In her limited spare time, Jeffries spends time making jewelry, putting together jigsaw puzzles, and reading.
Jeffries lives in Cary, North Carolina with her husband and son, Nick, who is autistic.