Stepping out of the Lindo Wing of St Mary’s Hospital in London with her new son in her arms on April 23, the Duchess of Cambridge was glossy and groomed for the world’s cameras just seven hours after giving birth.

While the hospital cameo by Kate, her husband Prince William and their little Prince Louis took only a few minutes, it was a precisely choreographed performance months in the making.

Behind the scenes, the new mother, 36, had a full team – not just of medical experts but key style advisers preparing her for the big moment.

Kate’s red Jenny Packham shift was a masterclass in literal dressing, referencing both Princess Diana’s 1984 leaving-hospital look and St George’s Day in one hit, but it is unlikely the idea was hers.

Princess Diana with Prince Harry in 1984 (left) and Kate Middleton in a very similar look 34 years later. Photo: Getty

With the Duchess still in labour, her stylist Natasha Archer dropped off the dress to the hospital, as she did with Kate’s baby debut outfits for Prince George’s birth in 2013 and Princess Charlotte’s three years ago.

According to her LinkedIn profile, Ms Archer – who lists her employer as ‘The Royal Household’ – has worked for the monarch’s family since 2007.

She started her career with the Cambridges as a personal assistant, but for the past five years has been identified as one of the Duchess’s vital image makers.

Natasha Archer with Kate’s bags in Assam on April 12, 2016 during the royal tour of India. Photo: Getty

She is credited with tempting Kate into Prada sandals instead of LK Bennett nude pumps, and Simone Rocha costume jewellery over heirloom diamonds. On her watch the Cambridge family has developed their trademark Pantone colour chart perfection.

While the palace has never confirmed Ms Archer’s official role as stylist, designers have spoken about how she sources outfit options for Kate’s engagements.

When the Duchess wore a grey Sentaler wrap coat, brand founder Bojana Sentaler said Ms Archer had “reached out” to the brand directly.

“The entire relationship is very organic,” Ms Sentaler said.

A month before a tour of India in 2016, Ms Archer was pulling together looks for Kate and emailed Mumbai-born designer Anita Dongre.

“We sent her a ‘look book’, then she came in and got some pieces for fittings,” Ms Dongre told The Telegraph, raving about how Ms Archer customised a printed georgette dress by turning its stole into a belt: “She’s amazing – it looks breezy and so contemporary.”

While her rise to Kate’s stylist was accidental, Ms Archer is no stranger to aristocratic circles. Fluent in Spanish and Italian, she went to a private boarding school in Leicestershire before graduating from King’s College in London with a Hispanic Studies degree.

Last year, she married royals photographer Chris Jackson in a French chateau near Bordeaux, her long-sleeved Jenny Packham gown echoing Kate’s own wedding dress.

Natasha Archer (left) and Amanda Cook Tucker (right) in Canada with the Cambridges in 2017. Photo: Getty

Also invaluable to Kate is hairdresser Amanda Cook Tucker, who trimmed William and Harry’s hair at her Knightsbridge salon when they were younger.

In 2012, Kate first entrusted what William has called her “nightmare” hair to Ms Cook Tucker for a tour of south-east Asia.

For £300 ($555) a day, she has since prepped the Duchess for everything from a three-hour hike in Bhutan to the cover of British Vogue’s centenary issue in 2016, and trims Kate’s hair at Kensington Palace every six to eight weeks.

Turns out you don’t need much to have duchess hair … just this.

Before the Cambridges’ Scandinavian tour this year, Ms Cook Tucker (who was behind Pippa Middleton’s wedding-day hair)  shared a now-deleted Instagram post showing what is in her war chest: two hairdryers, 13 brushes, seven combs, three curling tongs and six products.

Among the surprisingly affordable products: L’Oreal’s Elnett Supreme Hold hairspray and a frizz-busting coconut oil.