Question: The author of books about Ugenia Lavender was also in a pop girl group that was formed in what year?

full_context: Document 1: Bananarama: Bananarama are a British female pop music vocal group formed in London in 1981 by friends Sara Dallin, Siobhan Fahey and Keren Woodward. Their success on both pop and dance charts have earned them a listing in "The Guinness Book of Records" as the all-female group with the most chart entries in the world. In addition to their chart success, they are also known for their vocal style, generally singing in unison rather than in harmony like most vocal groups.
Document 2: Spice Girls merchandise and sponsorship deals: The Spice Girls were an English pop girl group that first came to international prominence with the release of their chart-topping debut single "Wannabe" in 1996. In 1997, the band became involved in an unprecedented marketing phenomenon, leading to a prolific number of Spice Girls merchandise and sponsorship deals. With the official Spice Girls branding on hundreds of different products, they became the most merchandised group in music history. The Spice Girls brand reportedly produced over £300 million worldwide through merchandise in 1997. Globally, the group's total grosses were estimated to have been $500–800 million by May 1998.
Document 3: Ugenia Lavender: Ugenia Lavender is the title character in a series of children's novels written by Geri Halliwell, who achieved fame as a member of the Spice Girls and as a solo singer-songwriter before deciding to pursue a career as an author. Halliwell began writing the books in 2004. Macmillan Children's Books announced that Halliwell had signed a contract to write six books featuring the character on 12 April 2007.
Document 4: Look at Me (Geri Halliwell song): "Look at Me" is a song by British singer-songwriter Geri Halliwell, who recorded and released it after leaving Spice Girls. Written and composed in collaboration by Halliwell, Paul Wilson, and Andy Watkins, it was released on 10 May 1999 as the first single from Halliwell's debut solo album, "Schizophonic." It peaked at number two at the UK Singles Chart, and at number three in both Australia and Canada. To promote the single, Halliwell performed the song on "Top of the Pops," "Party in the Park," "Wetten Dass", "Tickled Pink," "Tapis Rouge," "Musica Si," "Festival Bar 1999," "The Rosie O'Donnell Show," "Graine de Star," and "The Tonight Show with Jay Leno."
Document 5: Spice Girls discography: English girl group Spice Girls has released three studio albums, one compilation album, 11 singles and 18 music videos. Formed in 1994, the group was made up of singers Victoria Beckham ("Posh Spice"), Geri Halliwell ("Ginger Spice"), Emma Bunton ("Baby Spice"), Melanie Brown ("Scary Spice") and Melanie Chisholm ("Sporty Spice").
Document 6: Sugababes: The Sugababes are an English girl group formed in 1998 by Siobhán Donaghy, Mutya Buena and Keisha Buchanan. Their debut album, "One Touch", was released in the UK through London Records on 27 November 2000. The album achieved moderate success, peaking at number 26 in April 2001 and eventually being certified Gold. In 2001, Donaghy departed the group amid rumours of a rift with Buchanan and the group were dropped by their record label. With the introduction of Heidi Range, former member of fellow English girl group Atomic Kitten, the group began to experience a higher level of commercial success whilst keeping the critical acclaim they had achieved with their debut album. They released three studio albums before Buena announced her departure in December 2005, leading to Amelle Berrabah being brought in to replace her. Following the release of their first greatest hits album, the new line-up released two studio albums. In September 2009, after 11 years in the Sugababes, Buchanan, the final original member, was replaced by former UK Eurovision entry Jade Ewen. Range, Berrabah and Ewen released the group's seventh studio album, "Sweet 7", in 2010, after which they signed to RCA Records, before announcing an indefinite hiatus in 2011. In 2013, Ewen confessed that the Sugababes had split two years earlier. The original line-up of the band reformed in 2011, under the new name Mutya Keisha Siobhan.
Document 7: Geri Halliwell: Geraldine Estelle "Geri" Horner (née Halliwell; born 6 August 1972) is an English pop singer-songwriter, clothes designer, author and actress. Halliwell came to international prominence in the 1990s as Ginger Spice, a member of the successful girl group the Spice Girls; together they sold over 85 million records worldwide, making them the best selling girl group of all time. In 1998 Halliwell left the Spice Girls, though she rejoined the group when they reunited in 2007. Halliwell reportedly amassed a $40 million fortune during her last two years in the group.
Document 8: Spice Girls: The Spice Girls were an English pop girl group formed in 1994. The group originally consisted of Melanie Brown ("Scary Spice"), Melanie Chisholm ("Sporty Spice"), Emma Bunton ("Baby Spice"), Geri Halliwell ("Ginger Spice"), and Victoria Beckham, née Adams ("Posh Spice"). They were signed to Virgin Records and released their debut single "Wannabe" in 1996, which hit number one in 37 countries and established them as a global phenomenon. Their debut album "Spice" sold more than 31 million copies worldwide, becoming the best-selling album by a female group in history. Their follow-up album "Spiceworld" sold over 20 million copies worldwide. The Spice Girls have sold 85 million records worldwide, making them the best-selling female group of all time, one of the best-selling pop groups of all time, and the biggest British pop phenomenon since Beatlemania. Among the highest profile acts in 1990s British popular culture, "Time" called them "arguably the most recognisable face" of Cool Britannia, the mid-1990s celebration of youth culture in the UK.
Document 9: A Mother's Gift: A Mother's Gift is a 2001 novel by pop music singer Britney Spears and her mother, Lynne Spears. It is their second book together, following 2000's "Heart-to-Heart". The novel is loosely based on Britney's life. Popular reactions to the novel in spaces like Amazon were mixed. In 2012, rumors of a third novel sequel surfaced.
Document 10: Mel B: Melanie Janine Brown (born 29 May 1975), better known as Mel B or Melanie B, is an English singer, songwriter, presenter, television personality, dancer, actress, author, and model. Brown rose to fame as a member of the girl group the Spice Girls, in which she was known as Scary Spice. Brown is also known for supporting girl power and earlier global tours, which grossed an estimated $500–800 million between 1996 and 2000.
Document 11: Zoella: Zoe Elizabeth Sugg (born 28 March 1990) is an English fashion and beauty vlogger, YouTuber, and author. She is best known by her YouTube username Zoella. Her debut novel, "Girl Online", was released in November 2014 and broke the record for highest first-week sales of a first-time novelist since Nielsen BookScan began compiling such records in 1998.
Document 12: Melanie C: Melanie Jayne Chisholm (born 12 January 1974), better known as Melanie C or Mel C, is an English singer, songwriter, entrepreneur, actress and television personality. She is one of the five members of the Spice Girls, in which she was nicknamed Sporty Spice and with whom she sold over 85 million records worldwide. Melanie C began her solo career in late 1998 by singing with Canadian rock singer Bryan Adams on the song "When You're Gone". Her solo debut album "Northern Star" was released in 1999 and reached number four on the UK Albums Chart and was certified triple Platinum by the British Phonographic Industry (BPI). It produced four top fives and a top twenty single, two of which reached the number-one spot in the UK. Chisholm's second album, "Reason", was released in March 2003 and sold more than 500,000 copies. The album reached number five in the UK and produced one top ten, one top twenty and a double A sided top thirty single.
Document 13: Union Jack dress: The Union Jack dress was an item of clothing worn by singer Geri Halliwell of the Spice Girls at the 1997 BRIT Awards. The mini dress featured a flag of the United Kingdom, the Union Jack, on the front, and a white peace symbol emblazoned on the black-coloured back of the dress. The next day the images of the dress made the front page of various newspapers around the world, and is now remembered as one of the most iconic pop moments of the 1990s and Brit Awards history. The dress has become synonymous with the Spice Girls, Halliwell and the notions of Girl Power and Cool Britannia.
Document 14: Goodbye (Spice Girls song): "Goodbye" is a song recorded by British girl group Spice Girls. It was written by the Spice Girls, Richard Stannard and Matt Rowe, while it was produced by the latter two. The song became the group's first song without the vocals of Geri Halliwell. It was released by Virgin Records on 14 December 1998 as a Christmas single, along with the B-side, "Christmas Wrapping". The song was composed by Richard Stannard and Matt Rowe along with the remaining Spice Girls. It was later included as the eleventh and final track on their third studio album "Forever".
Document 15: Diary of a Chav: Diary of a Chav is a young adult series that was written by the English journalist, author, and broadcaster Grace Dent. The series consists of six books that were originally released in the United Kingdom from 2007 to 2009. An attempt to publish the books overseas in the United States was largely unsuccessful and only the first two books, re-titled for American publication, were released.
ground_truth: 1994