Princesses Beatrice and Eugenie twin in moment everyone missed

Princesses Eugenie and Beatrice are among the best-dressed members of the royal family, always pulling out the stops for special occasions.

Whether they're attendingRoyal Ascot or Wimbledon, or church services and weddings, the York sisters consistently look beautiful – and at a recent event that flew under the radar, they proved they can do casual cool just as well.

In December, the sisters attended a luncheon hosted by their mother, Sarah Ferguson, at London's exclusive Raffles Hotel, lending their support to their mum who was talking about the benefits of her favourite health clinic, Mayrlife.

While Duchess Sarah went for a formal look, donning her much-loved military-inspired red jacket, her daughters opted for laidback luxury, wearing matching black ensembles.

Both women wore super-soft black jumpers, with Princess Eugenie adding a gold pendant necklace to her look. She swept her hair into a casual ponytail and opted for hoop earrings.

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Princess Beatrice kept her jewellery minimal but wore her trademark auburn hair long, loose and beautifully blow-dried, as we've come to expect from the royal.

The photo was taken in early December, just weeks before Princess Beatrice welcomed her second daughter, Athena, and she certainly looks glowing at the special event.

Sarah Ferguson's luncheon

The afternoon soiree was held to introduce Mayrlife's philosophy to esteemed guests, according to the clinic's Instagram. "The event shared the transformative essence of holistic health and wellbeing inspired by [Sarah's] own personal experience and life-changing visit to Mayrlife. A celebration of wellness, vitality, and the path to lasting health amongst old and new friends," they wrote.

Princess Beatrice's best friend, nutritionist Gabriela Peacock was in attendance, too, with the health expert recently revealing that Beatrice is invested in her health just as much as her mother.

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"Bea is incredibly health conscious and she's very good with what she eats," Gabriela told HELLO! in November last year.

Though Beatrice's life pulls her in many directions, with royal duties and motherhood both requiring attention, Gabriela said her friend has her priorities in order. "She's very good at prioritising her children she's got a perfect kind of work-life balance as well."

Given her commitment to her health and wellness, we wonder if Beatrice plans to join her mother at Mayrlife? Sarah revealed she visits the exclusive health clinic every six months to reset and rebalance, and given she's just welcomed a new baby into the world, Beatrice certainly deserves to be looked after.