"who would the young princes marry?"
The Duke of York and Elizabeth Bowes-Lyon (1920s)
Public DomainThe Duke of York and Elizabeth Bowes-Lyon (1920s) - Credit: unknown

The 'young princes' are the unmarried sons of George V and Queen Mary: Prince Edward, the Prince of Wales, who would marry Wallis Simpson; Prince Henry, the Duke of Gloucester; and Prince George, the Duke of Kent.

Prince Albert of York (the Duke of York), who would become George VI on his brother's abdication, married Elizabeth Bowes-Lyon on 26 April 1923, so he was out of the running when Julia was a debutante in the 1923 season.