Kate Middleton may be a future queen, but she’s taking style cues from a different kind of princess.

The Duchess of Cambridge, 36, attended the Diplomatic Corps Reception at Buckingham Palace on Tuesday night wearing a glittering, pale blue gown by favorite designer Jenny Packham. The Cinderella-worthy dress included clusters of beads and silver sequins as well as a sparkling belt; the draped neckline extended into delicate cap sleeves.

The shimmering A-line gown, which appeared to be a custom adaptation of Packham’s newest bridal designs, matched perfectly with Middleton’s accessories: a diamond bracelet and jeweled box clutch.

To top off her Disney princess moment, she wore the special Lover’s Knot tiara, a favorite of both Middleton’s and the late Princess Diana’s. The duchess has worn the piece, which features teardrop-shaped pearls, on at least four other occasions.

She paired the sparkling crown with Princess Diana’s Collingwood Pearl Earrings, which Prince Charles gave his late wife as a wedding gift.