Answer by taking a quote from the following article:

Townsend was born in Leicester, the oldest of five sisters. Her father had worked at a factory making jet engines before becoming a postman, while her mother worked in a factory canteen. She attended Glen Hills Primary School, where the school secretary was Mrs Claricotes, a name she used for the school secretary in the Adrian Mole books. At the age of eight, Townsend contracted mumps, and was obliged to stay at home.

Townsend left school at the age of 14 and worked in a variety of jobs including packer for Birds Eye, a petrol station attendant and a receptionist. Working at a petrol station allowed her the chance to read between serving customers.  She married Keith Townsend, a sheet metal worker at 18; the couple had three children under five by the time Townsend was 23 (Sean, Daniel and Victoria), at which point the marriage ended and she became a single parent. In this position, Townsend and her children endured considerable hardship. In Mr Bevan's Dream: Why Britain Needs Its Welfare State (1989), a short book in the Counterblasts series, she recounts an experience from when her eldest child was five. Because the Department of Social Security was unable to give her even 50p to tide them over, she was obliged to feed herself and her children on a tin of peas and an Oxo cube as an evening meal. Townsend would collect used Corona bottles, to redeem the 4p return fee by which to feed her children.  Aged 13, her son questioned one Sunday why they didn't go to animal parks on weekends like other families. She later recounted that it was the start of her writing which became the Adrian Mole books, looking at life through the clinical eyes of a teenager but in a comedic manner. Townsend then chose to research the world of teenagers, and started attending youth clubs as a volunteer organiser. This led to her training as a youth worker.  While employed as a supervisor at an adventure playground, she observed a man making canoes nearby and, because he was married, put off talking to him; it was a year before he asked her for a date. It was at a canoeing course she met her future second husband, Colin Broadway, who was the father of her fourth child, Elizabeth. Subsequently, she became pregnant twice more, but underwent abortions. Ultimately, Townsend came to believe that termination is wrong. Ghost Children (1997) is a novel which draws on these experiences.  Her new partner encouraged her to join a writers' group at the Phoenix Theatre, Leicester, in 1978, when she was in her early thirties. Initially too shy to speak, she did not write anything for six weeks, but was then given a fortnight to write a play. This became the thirty-minute drama Womberang (1979), set in the waiting room of a gynaecology department. At the Phoenix, she became the writer-in-residence.  During this time she was mentored by several theatre directors including Ian Giles and principally Sue Pomeroy who commissioned and directed a number of her plays including Womberang, Dayroom, Groping for Words and subsequently Ear, Nose and Throat. She was also introduced to William Ash, then chairman of the Soho Poly (now Soho Theatre), who likewise played a significant part in shaping her early career. She met writer-director Carole Hayman on the stairs of the Soho Poly theatre and went on to develop many theatre pieces with her for the Royal Court and Joint Stock, including Bazarre and Rummage and The Great Celestial Cow. They later co-wrote two television series, The Refuge and The Spinney.  At the time of writing the first Adrian Mole book, Townsend was living on the Eyres Monsell Estate, near the house in which playwright Joe Orton was brought up. Mole "came into my head when my eldest son said 'Why don't we go to safari parks like other families do?' That's the only real line of dialogue from my family that's in any of the Mole books. It's in because it triggered it. I remembered that kind of whiny, adolescent self-pity, that 'surely these are not my parents.'"  The first two published stories appeared in a short-lived arts' journal entitled magazine, in the editing and production of which Townsend was involved, featuring the character then still called Nigel Mole. Actor Nigel Bennett had given her help and encouragement to persist with the work and sent the script to John Tydeman, the deputy head of BBC Radio Drama. The character first came to national awareness in a single radio play, The Diary of Nigel Mole, Aged 13 1/4 , broadcast by BBC Radio 4 on New Year's Day 1982.  Someone at the publishers Methuen heard the broadcast and commissioned Townsend to write the first book, The Secret Diary of Adrian Mole, Aged 13 3/4  which came out in September of that year. The publisher insisted on the change of name because of the similarity to Nigel Molesworth, the schoolboy character created by Ronald Searle and Geoffrey Willans. A month after the book's appearance it had topped the best seller list and had sold a million copies after a year. Adapted as a play, the stage version premiered in Leicester and ran at Wyndham's Theatre for more than two years. The first two books were seen by many as a realistic and humorous treatment of the inner life of an adolescent boy. They also captured something of the zeitgeist of Britain during the Thatcher era.  The Growing Pains of Adrian Mole (1984) was reputedly based on her children's experiences at Mary Linwood Comprehensive School in Leicester. Several of the teachers who appear in the book (such as Ms Fossington-Gore and Mr Dock) are based on staff who worked at the school in the early 1980s. When the book was televised, it was mostly filmed at a different school nearby. Mary Linwood Comprehensive was closed in 1997.  These first two books were adapted into a television series, broadcast in 1985 and 1987.

How many Adrian Mole books did Sue Townsend write?