At the 2014 Remeberance Day ceremonies at the Londaon Cenotaph, the Duchess of Cornwall was wearing the brooch of the 12th Lancers which was her father's regiment.
Major Bruce Shand fought in WWII winning 2 Military Crosses !
an example
She has worn this badge before such as the 70th anniversary commemorations of the D-Day landings back in June of this year.