Geraldine Estelle "Geri" Halliwell

In late 2004, Halliwell made a return to music with the single "Ride It", which reached number four in the United Kingdom and number one on the dance charts. However, several months elapsed before another single was released, during which time she was apparently instructed to record some new tracks for the as yet unreleased album by her record company, which was unhappy with the setlist. Halliwell planned her first solo tour of the United Kingdom and Ireland, but due to lack of ticket sales, compounded by the label's pressure on Halliwell to record additional songs, led to the cancellation of the tour. Eventually a new single, "Desire", was released on 30 May 2005, reaching number 22 in the UK Singles Chart and number one on the UK Dance Charts. Released shortly after, the album Passion similarly received little attention from the public or critics, and stalled at number 41 in the UK charts. Halliwell's recording contract with EMI was subsequently not renewed, and in recent interviews Halliwell has stated that she is not interested in recording another album at the moment and was content with writing children's books and being a mother.
• 2007–2009: Spice Girls re-union and Ugenia Lavender
On 28 June 2007, Halliwell announced she was joining her former group-mates for a concert tour "Return of the Spice Girls". Part of the setlist of the reunion tour features Halliwell performing solo, singing her cover of It's Raining Men. It was announced on 1 February that the tour would end early, on 26 February 2008.
On 12 April 2007, it was announced that Halliwell had signed a six-book deal with Macmillan Children's Books. The books follow the adventures of nine-year-old Ugenia, a character based on Halliwell, alongside her friends Bronte, Rudy and Trevor. Other characters are said by Halliwell to be loosely based on Gordon Ramsay, George Michael, Marilyn Monroe, Vincent van Gogh, Wayne Rooney and the character Justin Suarez from the TV series Ugly Betty. The character Princess Posh Vattoria, a caricature of Halliwell's bandmate Victoria Beckham, was featured in early drafts but has not appeared in the book series.