The transformation of Mary Donaldson of Bondi Junction to the soon-to-be Queen Mary of Amalienborg Castle in Copenhagen is providing an unexpected boon in her homeland, not least for those in the business of princess training.

Twenty-three years after the then 28-year-old marketing executive enroled in Teresa Page’s $1195 (NZ$1285) eight-week “StarMakers” deportment course, Sydney’s “princess whisperer” can take some of the credit for her metamorphosis into a glamorous Euro royal.

Page says increasing demand thanks to a resurgence of interest in all things Mary has inspired her to relaunch her classes to teach a new generation the art of walking, talking and smiling in a way that allows one to “radiate light”.

Page’s eager student, who she first met at their local eastern suburbs gym, enroled in the course five weeks after she had secretly met and partied with Crown Prince Frederik at the Slip Inn during the Sydney Olympics. The lovebirds “connected” over a mutual love of horses and fitness, according to media coverage at the time.

For four hours each Sunday, Mary learned how to “embrace the spotlight, develop a new self-image, set extraordinarily high goals and manifest dreams”.

“I teach students to think of the camera as their best friend, to smile with relaxed confidence, to be fluid and engaged so that every frame is a good one that captures your ‘light’ which we all radiate,” Page enthused as she recalled helping Mary improve her gait in a Darlinghurst studio.

“The course is about using those same principles across other aspects of life, like when she walks into a room and meets people. She was definitely on a path of self-development.”

While Page has had limited contact with Princess Mary since she graduated, she still has several videos of the Tasmanian native during her time in the course, which also included scripted acting sessions, an improvisation class, and tutelage on how to access her “vulnerability” to appear more approachable in photos.

In the videos, Mary Donaldson is at first shy and nervous, but soon begins to blossom in front of the camera. In one clip Page shared with this masthead, her star pupil, wearing a pink knee-length skirt, high heels and casual white top, is seen walking across a room learning how to turn “correctly”, being reassured that “practice makes perfect” when it comes to improving her stride.

Eventually, Mary looks confident and poised. Over the course of the filming she reportedly lost 5 kilograms.

Just as Julie Andrews’ character Queen Clarisse Renaldi of Genovia in The Princess Diaries instructed the ungainly Anne Hathaway’s Mia Thermopolis that royalty “do not schlump”, it was Page who taught the future Princess Mary “how to enter a room with grace and poise”.

“Mary has been very good for my business … I don’t need to advertise,” Page admitted this week, saying she spent years researching and perfecting the course after a decades-long career of modelling and acting.

However, her previous brushes with royalty extended only to portraying the Queen of the Ptolemaic Kingdom of Egypt in a big-budget TV commercial for Cleopatra soap in the late 1980s.

Page vividly recalls the day she realised her former pupil was dating the Danish royal. The smitten brunette missed her final lesson to go on a date with Prince Frederik, who had quietly slipped back into Sydney during their early courtship days.

“She told me she had family from overseas visiting … months later I saw her photo on the front page of a newspaper, all done up with Prince Frederik. I said out loud, ‘that’s our Mary!’ She was a very eager student, she had a sense of urgency about learning how to project herself,” Page said.

Decades later, Page insists her StarMaker classes remain just as relevant today, and after a three-year hiatus, she is about to launch them online.

However, she’s entering an increasingly crowded market. Plans are afoot for the June Dally-Watkins school to reopen its doors in Sydney this year offering similar “self-improvement” courses, while the Sydney School of Protocol is already running classes on how to use a knife and fork, along with “correct table posture”.

June Dally-Watkins’ managing director Jodie Bache-McLean, who first studied under the late “Miss Dally” 41 years ago, described Princess Mary as “a magnificent role model for young people”.

“We teach people to be gracious and have empathy for others, to be polite and confident … for a lot of young people glued to their phones, those skills are not being learned. I think the coronation of Queen Mary will be an inspiration for a lot of young girls to learn these forgotten skills,” she said.