Jane Hildreth is an agent for British Intelligence.
She bears that title for having been married to Lord John Hildreth for four years in her early 20's. Educated at Roedean and Girton College, Cambridge, she was completing her law degree when they met and fell in love. With the divorce, said to have been one of the cleanest and friendliest in years, she retained the title until she remarried and her settlement was considerable, making her set for an easy life.
She is 35 years old at the start of the series. She stands 5'2" tall and has a very slender build. Her hair is described as "fair" and is nearly shoulder-length. She says that she is considered very pretty by most people but certainly not beautiful. Besides the stone "cottage" she has in the Cotswolds, the region of England where most of the action in the books take place, as well as a very nice house in London and a Manhattan apartment.
Once her divorce was final, Hildreth took a job as a public relations consultant for an international cosmetics company and stayed at that for four years. Then she made a rather drastic change in career and life.
Hildreth had always had natural fears of snakes and dark places and the like but after her divorce, her list of frightening things kept growing until she became angry at herself and decided to break out of the phobia business. Her determination took her eventually to join the Metropolitan Police to become a police officer. After a couple of years there, she accepted the offer to work for the security service.
Now she uses her aristocratic status and experience to mingle with the jet-set and to be accepted in situations most of the SIS would not fit in. Money attracts money which attracts those who want more and who will do anything to get it. Hildreth is there to stop it from going too far.