That is incorrect. Caroline's title and style as a royal highness and princess of the UK through her marriage to Prince Ernst August takes precedence over her birth status as HSH Princess de Monaco.
She is correctly addressed as "HRH Princess Caroline, Princess von Hannover". She was born a princess so she is entitled to hold it before her christian name.
The title "Hereditary Prince" is held only by a son of a regining Prince de Monaco. The name "Marquis de Baux" is held as a courtesy title as it is no longer recognized by the French Republic as being a valid name, but simply an acquisition of marriage for the Grimaldis during centuries past.
The French Republic only recognizes the sovereign titles of former rulers of France as legal. This includes the Count de Paris (Orleans), Prince/Princess Napoleon (Imperial Family) and the ducal titles of the Bourbons.
She is correctly addressed as "HRH Princess Caroline, Princess von Hannover". She was born a princess so she is entitled to hold it before her christian name.
The title "Hereditary Prince" is held only by a son of a regining Prince de Monaco. The name "Marquis de Baux" is held as a courtesy title as it is no longer recognized by the French Republic as being a valid name, but simply an acquisition of marriage for the Grimaldis during centuries past.
The French Republic only recognizes the sovereign titles of former rulers of France as legal. This includes the Count de Paris (Orleans), Prince/Princess Napoleon (Imperial Family) and the ducal titles of the Bourbons.