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

Context articles: Spice Girls
Bandana (pop band)
Ugenia Lavender
Happiness (Japanese band)
Preluders
Flower (Japanese band)
GI (band)
People Say (song)
Girl Authority
TrueBliss

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.
Bandana is an Argentine pop girl group formed in 2001.
 Following the international trend of teen pop girl groups established by the Spice Girls, the five members of Bandana — Ivonne Guzmán, Lourdes Cecilia Fernández, Valeria Gastaldi, Virginia Da Cunha and María Elizabeth Vera — were selected on the TV show "Popstars" and were a carefully marketed product that became a phenomenon in the country, particularly among young girls.
 Their self-titled debut album was released in 2001 on Sony BMG Records, led by the hit single "Guapas", and was certified four-times platinum by the CAPIF.
 Despite being initially snubbed by many critics and artists, Bandana emerged as Argentina's best-selling act since 2001.
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.
Happiness is a Japanese pop girl group formed by LDH in 2008 and signed to Rhythm Zone.
 They are a dance and vocal unit of collective girl group E-girls alongside Dream and Flower.
 The group consists of two vocalists and five performers.
The Preluders were a pop girl group from Germany.
 The original group comprised singers Tertia Botha, Miriam Cani, Anh-Thu Doan, Rebecca Miro, and Anne Ross.
 Created through the ProSieben talent show "Popstars - Das Duell" (2003) in which pop groups of both genders competed against each other, Preluders lost out to boy band Overground in a public vote.
 Despite their defeat, the group achieved commercial success with their first single "Everyday Girl", which became a number-one hit in Germany, while their full-length debut album "Girls in the House" (2003) reached the top five in Germany and Switzerland.
Flower is a Japanese pop girl group formed by LDH in 2009 and signed to Sony Music Japan.
 They are a dance and vocal unit of collective girl group E-girls alongside Dream and Happiness.
 The group consists of one vocalist and five performers.
Global Icon (Hangul: 지아이; acronym: GI) was a South Korean girl group formed by Simtong Entertainment in 2013.
 They released their debut single "Beatles" on April 3, 2013.
 The group originally debuted with a "boyish" concept, referring to the fact that the majority of the members had short hair and a more masculine attitude and style, opposed to the feminine concepts many Korean pop girl groups have, but after their line-up changes, the group returned in 2015 with a feminine and sexy concept.
"People Say" is a hit single written by the Jeff Barry and Ellie Greenwich songwriting team and made popular by the American pop girl group The Dixie Cups.
 It was originally released in July 1964 on the Red Bird Records label.
 The song was arranged by Mike Stoller.
 "Billboard" named the song #53 on their list of 100 Greatest Girl Group Songs of All Time.
Girl Authority was an American pop girl group.
 The group consisted of nine girls, at the time, ranging in ages 8 to 13; Jacqueline Laviolette, Carly Grayson, Jessica "Jess" Bonner, Crystal Evans, Kate Barker, Zoë Virant, Jessica Tarr, Gina Miele and Alexandra "Alex" Bilbo.
 The group was established in the summer of 2005 by the group's vocal coach/executive producer Samantha Hammel, Scott Billington (a Grammy award-winning producer) and the CEO of Rounder Records, John Virant, the father of Zoe, one of the members of Girl Authority.
 Based on the oldest girls graduating high school; in the summer of 2010, the girls contracts with Rounder Records ceased, and the band officially retired.
 Currently, the majority of the group members are attending or just graduating college.
 All of these girls are still close friends and get together for reunions.
TrueBliss were a New Zealand pop girl group formed in April 1999.
 The band were formed on the popular television show "Popstars", which aired on TV2 for nine weeks in the search for a new girl group.
 TrueBliss were the first ever group to be formed under the "Popstars" banner, before the concept was sold to Australia (who formed the group Bardot in similar style), continental Europe, the UK and the United States.