The Princess of Wales performed a solo engagement at the Royal Marsden Hospital on Tuesday

Prince William has sparked speculation following Kate’s nod to Princess Diana.

The Princess of Wales performed a solo engagement at the Royal Marsden Hospital on Tuesday, marking the occasion with a meaningful new addition to her jewellery collection.

Kate chose to debut a pair of Cartier Trinity hoop earrings worth £3,000 during her visit to the South Kensington hospital, where she had undergone her preventative chemotherapy treatment in 2024.

Tatler reported that the choice of jewellery could potentially be a birthday gift from Prince William, following his touching social media tribute praising her “remarkable strength” and role as “the most incredible wife and mother.”

The princess was wrapped up in a Blaze Milano winter coat and a Gabriela Hearst jumper, accessorising with a Morgan small handbag by Asprey and the new hoops featuring three intertwined bands in white, yellow and rose gold.

The iconic Trinity collection by Cartier celebrated its centenary last year, boasting an impressive list of celebrity admirers throughout its history.

Grace Kelly and Romy Schneider were known for their love of the classic Trinity ring, while actress Jacqueline Bisset frequently wore a chunky bracelet from the range.

The design’s origins are steeped in mystery, with some pointing to ancient Celtic roots while others trace it to Russian wedding rings.

Kate has demonstrated her own affinity for the collection over the years, wearing a chunky Trinity necklace at the National Portrait Gallery in 2012 and again in New York in 2014.

She also owns matching glittering earrings, which she wore at a SportsAid banquet at Kensington Palace in 2016.

The princess further expanded her Trinity collection with a more subtle set, including a small necklace and diamond-set studs, first spotted during a 2017 Paris visit.

During her visit, Kate spoke candidly about her experience at the hospital, saying: “I was just saying, coming in the front entrance here, having made so many quiet, private visits, actually it’s quite nice.”

Princess Kate beamed as she walked through the Royal Marsden HospitalGetty

The princess later announced her remission on social media, expressing gratitude to those who supported her and William through the adjustment to their “new normal.”

In a significant development, Kate has been named joint patron of the Royal Marsden Hospital alongside Prince William, who has served as President since 2007.

The princess offered support to fellow patients and personally thanked staff members for their exceptional care during her cancer journey.