She debuted a new pair of shoes for the evening event. They’re by Prada. They’re the company’s Wavy-Cut Suede Pump in black.
They feature a pointed toe (which Kate seems to be a big fan of at the moment, I notice!) a three-inch heel and cutout detailing. Unfortunately, the shoes are no longer available for purchase (they’re from a past season). It looks like they originally retailed for $750 USD.