Back in July 2003, she performed in London's Hyde Park. I know because I was there, reporting on the gig for this very website.
If you'd have told either of us then it would take 14 years for her to sing there again, I doubt we would've believed you.
Back then Shania - no surname required - was riding the crest of a wave. She'd had hit after hit, recorded the best-selling country album of all time (1997's Come On Over) and been the half-time act at the Super Bowl.
Not long afterwards, though, it began to go wrong. Her marriage to producer Robert "Mutt" Lange collapsed, and she developed debilitating vocal problems that forced her to temporarily give up recording and performing.
The comeback trail began in Las Vegas with a two-year residency at Caesars Palace that paved the way for a "final" tour in 2015.
The singer has sold more than 90 million albums worldwide
Now, 20 years on from Come On Over, Shania is back - with a new husband, a new album (called Now) and a new voice.
"It is different," she says of the celebrated purry twang that brought us tracks like You're Still The One, That Don't Impress Me Much and Man! I Feel Like A Woman.
"I've got smokier sounds I never had before, and I've got a lower register than I used to have before."
The singer blames Lyme disease for her dysphonia, an ailment that causes the vocal cords to seize up when speaking or singing.
"It'll never be solved," she tells the BBC. "It's a permanent problem.
"But with a lot of physical and vocal therapy, I've got better at understanding my voice and better at managing it."
Our interview takes place towards the end of a hectic week that also includes appearances on The One Show, Strictly Come Dancing and Radio 2 Live in Hyde Park.
If Shania is feeling the strain, though, it's not showing on a face once adjudged to have a perfect set of geometric measurements.
Shania will be seen next year making her film acting debut
Now, she insists, is not a break-up album - despite having songs that specifically reference the extramarital affair Lange had with her best friend.
"Can't believe he'd leave me to love her," she sings on Pour Me, the record's most transparently autobiographical number.
"That's my divorce low moment," she admits. "That's me indulging and just feeling sorry for myself. But there are so many songs on the album that have nothing to do with my divorce at all.
"It's about the journey of my whole life and all the disappointments I've been through. It's about the ups as well as the downs."
The former are perhaps best illustrated by Life's About To Get Good, a breezy singalong that serves as the album's lead single.
The video for the song was shot in the Dominican Republic - thankfully before Hurricane Irma - and required the loan of a certain piece of headgear.
"I actually borrowed the Man! I Feel Like A Woman outfit for the video, top hat and all," she says of a costume that now has pride of place at Nashville's Country Music Hall of Fame.
Earlier this month she appeared on the Strictly Come Dancing launch show
"It was really fun for me to revisit that image, but we had to rush it back for the display before anyone missed it."
It's a busy time for Shania, who'll be seen next year making her big-screen acting debut opposite John Travolta in racing car drama Trading Paint.
"John reached out and asked me to do it," she says of the Grease and Pulp Fiction star. "I play a schoolteacher, so it's a whole new zone."
The new husband, by the way, is Frederic Thiebaud, the former husband of the same best friend with whom her ex had that affair.
While we chat in an adjoining hotel room, the genial Swiss sits with a computer on his lap, hunting online for a vegetarian restaurant where they can have dinner later.
I am sorely tempted to make a comment about Twains never meating, but I fear my pun may get lost in translation.
Now is released on Virgin EMI on 29 September.