The list included tennis star Serena Williams, who looked absolutely chuffed at the news, and Princess Beatrice, whose jaw dropped and, more to the point, who until now no one knew had a personal social media account.
In her excitement, bride-to-be Karlie tagged @beayork, an account which is private and only has 651 followers, including Beatrice’s mum, Sarah Ferguson, Prince Harry’s ex-girlfriend, Chelsy Davy, and supermodel Cara Delevigne.
Thankfully, Karlie's error probably won't get Beatrice in trouble: royals with formal working roles - such as the Duke and Duchess of Cambridge - aren't allowed to have personal social media, but for those who have jobs outside the family, it’s permitted.
Princess Eugenie recently made her Instagram account public - the only British royal to do so. Maybe now Beatrice will follow suit.