For the opening of Evelina London's new children's surgery unit, Kate returned to her go-to ensemble of an Alexander McQueen pantsuit in dark blue ... Diana's diamond and sapphire earrings.

On this occasion, Sofia opted for her dark blue sapphire toppers ... the royal wore sapphire drop earrings and a diamond bracelet. Also in attendance was Sofia's sister-in-law, Crown Princess ...

Accessorizing a full-length blue and green tartan trench coat from Holland Cooper, Kate wore a dazzling pair of sapphire and diamond earrings borrowed from the Queen for the event on Thursday.