Born near Southampton in 1911, Gwendoline Courtney was the daughter of antiques dealer Edwin Courtney, and his wife Joanna. She was distantly related to author and educator Arthur Mee, and first cousins with Phyllis Norris, who wrote a number of books for girls. The family moved to Wallasey when Courtney was young, and she was educated at Oldershaw High School. She worked for a time in her father’s office, before joining Lord Goodman’s staff, during WWII, and prided herself on being the only civilian to work on Operation Overlord. After the deaths of their parents, Courtney and her two sisters lived together for the rest of their lives, moving from place to place - Courtney had sustained an ear injury, during a bomb blast, that made quiet absolutely essential - as the need arose. She died in Shaftesbury, in 1996.

Beginning with Torley Grange, published when when she was twenty-four, Courtney produced thirteen book for young readers. Her work fell out of favor during the 1960s, but she continued to write and lecture extensively. She was very active in various societies related to her interests, such as the West Country Writers Association, the Cornish Cat Society, and the Salisbury Fencing Club. She was also much involved in amateur theatricals, writing, producing and acting in plays.