In September 2007, Brown joined the fifth season of the US television dance competition, Dancing with the Stars with her partner Maksim Chmerkovskiy. On 27 November 2007, they took second place in the show, losing to Hélio Castroneves and his partner, Julianne Hough. That year, the Spice Girls re-grouped and announced plans for a reunion tour, from which they were said to have earned £10 million each (approximately $20 million). The band said that they are still enjoying doing their "own thing". The group decided to release their first compilation album, Greatest Hits, in early November 2007 and the tour began on 2 December 2007. During one Spice Girls performance at London's The O2 Arena, the band's children, including Brown's children accompanied her on stage during "Mama", along with the other Spice Girls' children. During the reformation filmmaker Bob Smeaton directed an official film of the tour entitled Spice Girls: Giving You Everything. As well as their sell-out tour, the Spice Girls were contracted to appear in Tesco advertisements, for which they were paid £1 million each. After splitting for a second time the Spice Girls once again reunited for a special performance at the 2012 London Olympics closing ceremony in August 2012 where they performed "Wannabe" and "Spice Up Your Life".
Brown became the subject of tabloid stories during her relationship with Hollywood actor Eddie Murphy, who fathered Brown's second child, Angel Iris Murphy Brown, born 3 April 2007. By early December 2006, Brown and Murphy had separated. Murphy told a journalist that the parentage of Brown's unborn baby could not be proven until a paternity test was performed. On 22 June 2007, a court-ordered DNA test confirmed that Murphy was the child's father. Murphy admitted paternity and indicated that he and Brown had reached a paternity settlement of $7 million.
In February 2007, Brown began dating Stephen Belafonte. The couple secretly married on 6 June 2007 in Las Vegas, Nevada, US at A Special Memory Wedding Chapel. They renewed their vows in front of their families on 8 November 2008 in Hurghada, Egypt. On 1 September 2011, Brown gave birth to her third daughter, Madison Brown Belafonte.