Geri Halliwell says watching The Spice Girls' children play together is "beautiful".
The 35-year-old singer has revealed her 20-month-old daughter Bluebell goes on "play dates" with two-year-old Cruz, the son of her bandmate Victoria Beckham.
Geri wrote on her blog: "Bluebell loves hanging with the Beckham boys. Cruz and Bluebell have play dates, and Romeo - well, he is just gorgeous with her.
"Actually, it was a beautiful moment when we were rehearsing the other day and all of our kids were playing on the stage at the same time. It made me smile."
Victoria has three sons with soccer star husband David - Cruz, Romeo, five, and Brooklyn, eight - while Emma Bunton gave birth to her son Beau in April.
Mel B has two daughters, eight-year-old Phoenix Chi and seven-month-old Angel Iris.
The band begin 'The Return of the Spice Girls' world tour in Vancouver, Canada, on December 2, and Geri insists their meticulous preparations have meant the girls have been living in each others pockets.
She said: "I actually feel like I'm in the Spice bubble! We are encapsulated in this world where we are just immersed in each other's lives constantly.
"Just before the run-through of the show the other morning, Mel B, Victoria and I even went to the toilet together. Although we did use separate cubicles!"