The former Spice girl – who also has sons Romeo, nine and Cruz, seven, as well as nine-month-old daughter Harper with her husband David Beckham – only realised she had left Brooklyn in their Los Angeles house when she was driving down the road.
She said: “I jumped in my Range Rover, put the car seat in, put my iPod on and drove to school.
“And then I realised I’d left Brooklyn in the kitchen.
“I was driving along, talking away, and all of a sudden, I looked down at the seat, and I was like: Shitt! S**! I’ve forgot something.”
The 38-year-old star admits she “felt like such an idiot” when she realised her mistake and had to turn around immediately and drive back to collect Brooklyn.
She added to Vanity Fair magazine: “I felt like such an idiot because I was in a huge rush.
“Harper was in the car, I was in the car, and we were on the way to school – but we did not have the child who needed to go to school.”
“I’d gotten down the road, and I literally had to turn around and drive straight back.”
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