The physical similarities of Kate, Pippa and Carole Middleton are often noted: dark eyes, dark hair, beautiful skin tone and athleticism. Admittedly, the 32-year-old Duchess of Cambridge is taller and slimmer - not to mention more impeccably groomed - than her younger sister, Pippa, 31, and mother, Carole, 59, but undeniably, the trio display all the advantages of excellent genes.
o, it's no surprise then that the Middleton women are fond of the same designers: Alexander McQueen, Alice Temperley and Mulberry at the higher end; Zara, Reiss and LK Bennet for their more affordable staples.
However, the latest addition to their wardrobes is undoubtedly Orla Kiely. Indeed, since 2012, all three have been spotted in striking items from the Irish designer's recent collections.
Evidently, it's been an association which has proved fruitful. Indeed, the designer - who also has an extensive range of luggage, stationery, wallpaper, homeware and furnishings - has just, this week, announced that profits at the company have spiked 32pc in a year.
Key to Orla Kiely's continued appeal to the Middleton clan is her classic approach to versatile clothing. Dresses are not made unnecessarily fussy with layers of fabric; coats follow a flattering A-line shape; skirts are not too short; and jackets are well-made and well-structured.
Kate's first outing in Orla Kiely involved a retro-print brown and cream patterned dress, which she wore in Oxford in February 2012. The item, which was then on sale for €200 after being reduced from €415, inevitably sold out within minutes.
She dug the same dress out from her wardrobe again a year ago for another event in London - the long sleeves and wool material being ideal for chillier months. Just a day after that reappearance, and in another area of a wind-swept London, she wore a navy Orla Kiely skirt teamed perfectly with a MaxMara jacket, a €325 Russell and Bromley blue suede bag, and Alexander McQueen heels.
But perhaps her most celebrated look came in March 2012. Then, the duchess really wowed in a charcoal grey dress with three-quarter length sleeves, black daisy detail at the neckline, and a pleated skirt from the label's AW11 collection.
Meanwhile, for the high-profile royal flotilla on the river Thames in June 2012, Pippa opted for Orla's chic navy skirt and matching jacket with cream trim. Later that month in the royal box at Wimbledon, she wore a demure dress - also in navy - along with a knitted Orla Kiely navy and white patterned jacket
All eyes were on Carole Middleton when she showed up at the London hospital where her daughter had just given birth to Prince George in the summer of 2013. And she got her look just right wearing one of Orla's dresses: a pale blue patterned tea-dress that fell to the knee.
Interestingly, in September at the Vinyl Factory in trendy Soho, Orla Kiely's SS15 showing was particularly packed. The requisite fashion bloggers and glossy magazine editors were, of course, all there, along with a spattering of celebrity. However, also in attendance was a significant contingent of Sloane Rangers - the playful moniker given to London's prim and privileged set. On offer was Orla's signature 1960s-inspired style: plenty of pretty smock dresses to the knee, loose-fitting trousers, cocoon coats and simple, classic styles of skirt with accompanying jackets. In short, her collections are perfect princess attire.
Now aged 50, and based in London with a flagship store in Covent Garden, Orla was born and raised in Dublin. Married to Dermott Rowan, their sons - Robert and Hamish - are aged 19 and 17 respectively. The family also has a beloved labradoodle, Olive, who regularly goes to work with her famous owner.
After graduating from NCAD in Dublin, the designer left her home city some 20 years ago, once stating simply, "there was nothing going on in Ireland, especially not in design". She initially found a job as a print designer for Esprit, but she later went to the Royal College of Art - where she lectures today - to do an MA in fashion. Upon graduation, she worked for a stint with Ralph Lauren, but soon began creating her own designs at the weekend, before slowly building her business into the global brand it is today.
Orla herself has always maintained a discreet approach to her more famous customers - something Kensington Palace in particular values greatly. She has largely refused to be drawn in on what it's like to have the world's most watched woman wear one of her creations, although she has politely said in the past that Kate "looks absolutely great" in the clothing.
One of the reasons that Orla Kiely's London Fashion Week show was quite so packed in September was because just about everyone expects Kate - as well as her mother and sister - to emerge in another one of Orla's pieces. In fact, more than one fashion website went to the trouble of singling out the top duchess-friendly looks from the show.
It's not known if Kate has snapped up another Orla Kiely creation. However, now that she is four months pregnant, the A-line dresses in particular would accommodate her baby bump well.
Commenting on the increased profits, Dermott Rowan - company CEO, as well as Orla's husband - was, this week, keen to stress that Orla Kiely is not a flash-in-a-pan brand, sustained only by royal connections.
"This follows 20 years of hard work from our brilliantly talented team, together with constant reinvestment," he says.
Of course, Orla Kiely is truly one of Ireland's most successful international designers (in 2010, An Post issued a limited edition stamp in her honour alongside fashion greats Philip Treacy, John Rocha and Paul Costelloe).
Her brand will most certainly continue to expand - aided, at least in part, by that precious royal seal of approval.