With appearances at Royal Ascot and Wimbledon, Peter Phillips's girlfriend, Harriet Sperling, has become a firm fixture in the royal fold this summer. The stylish NHS nurse—who was given the ultimate stamp of approval from King Charles by riding in a Royal Ascot carriage—wore a pale blue linen skirt set while taking in the tennis championships last week, and on Friday, she brought out one of summer's biggest dress trends at the Royal Charity Polo Cup 2025.
Sperling joined Princess Anne's son at Guards Polo Club in a breezy ivory midi dress from St. Clair, a London-based label that's become increasingly buzzy among British it girls. I spotted numerous women in St. Clair dresses at Royal Ascot (and on the streets of London) this year, and Princess Kate's former personal assistant, Natasha Archer, regularly wears the brand.
Sperling beat the heat in the label's Edwina sleeveless shirt dress, with the organic cotton design featuring a swirly skirt and an "antique-inspired floral embroidered yoke," per St. Clair.
The dress follows in the footsteps of Princess Eugenie and Queen Elizabeth's cousin Flora Vesterberg, who both wore crisp white dresses to beat the summer heat over the past month.
Sperling gave her look a pop of color with a deep purple Anya Hindmarch crossbody bag, and like she did at Wimbledon, the pediatric nurse wore a pair of Penelope Chilvers shoes. She swapped her chunky platform sandals for a Duchess Sophie-approved style, wearing tan leather espadrille wedges with a ribbon tie at the ankle.
While Prince William competed in the annual charity polo event, the Princess of Wales skipped attending this year's match, which she last attended in 2023.
Sperling's appearance marks the second time the royal girlfriend has attended the Royal Polo Cup after making her debut at the event with Phillips last summer. The couple made their first public appearance at the Badminton Horse Trials in May 2024 and have been going strong ever since, with her inclusion in a carriage at Royal Ascot said to be a marker that an engagement could be on the way for the couple.
