Now married to Red Bull chief Christian Horner, her love of the Hornets has not subsided while they still languish in the Championship.
After getting relegated in 2022, many expected Watford to bounce back with their squad.
But with more managers than Spice Girl hits, they ended up finishing 11th in a disappointing campaign that saw Rob Edwards, Slaven Bilic and Chris Wilder all in the hotseat.
What made it even worse, though, was Edwards making his way up the M1 to Luton, where he became manager after Nathan Jones' unsuccessful trip to Southampton.
It turned out to be a blessing in disguise as the Hatters flew up the table and into the play-offs.
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There, they beat Sunderland before defeating Horner's beloved Coventry in the final on penalties.
But while the Team Principal of the Red Bull Formula Team was hurting, he was not the only one.
In an exclusive chat with talkSPORT, Horner revealed how his wife was crushed by Luton's promotion as a diehard Watford fan.
Speaking about Coventry falling at the last hurdle, he said: "They came so close, what a cruel way to go out on a penalty shootout the way they did.
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"I thought they played so, so well this last season. So hopefully they can go one better [next season] and make it through without the stress of the play-offs."
As the conversation turned towards Geri, Horner said: "As a Watford fan, she was gutted to see Luton get through.
"I think there is a local rivalry between Watford and Luton.
"Certainly, my step-father was a bit annoyed about it.
"But Geri appreciates all sport and I think she is looking forward to seeing Watford get back there soon as well."
Horner was then asked how many Spice Girls could he name in 20 seconds, his initial reaction? "Oh, Christ…"
But if Geri is reading, you might have to whack on a Greatest Hits album because Horner could only name four, listing: "Wannabe, Stop Right Now, there's Mama, there is Two Become One…"
Just be glad Scary Spice was not in the building…