The 43-year-old singer - who made up one fifth of the girl group - has admitted she found it difficult living with the girl band when they first formed in 1994 because there wasn't enough space in their ''small three-bedroom'' house they shared in Maidenhead, England.
Speaking to MarieClaire.com, the red-headed beauty said: ''Five girls living together in a small three-bedroom house in Maidenhead, just outside London, was lots of fun, albeit at times tricky.''
However the 'Wannabe' hitmaker has revealed she found it easier to leave her family home and move in with Victoria Beckham, Mel C, Mel B and Emma Bunton because she had moved out before, although she thinks her housemates soon discovered she was a ''bossy'' housemate.
She explained: ''I was the oldest at 22 and had already experienced living away from home, so the other girls probably found me quite bossy.''
And Geri - who was known as Ginger Spice in the band - has revealed the girls swiftly became like a family and she developed a close bond with everyone.
She said: ''Emma was the youngest at 18; she was like the little sister I never had, and I adored her immediately. Mel B and I became partners in crime, always getting into trouble together. Victoria and I had an equal relationship. And Melanie C and I shared a childlike fascination for pop music and had big dreams of making it.''
Meanwhile, Geri has admitted she would walk around as if she was famous even before the band was known.
She explained: ''During our first year together as the Spice Girls, on a weekend when Emma and Victoria went home to visit their families, Mel B, Mel C, and I went to Camden Market ... We weren't famous yet, but strutted like we were.''
It's time for a riot grrrl revolution.