Her personal flag consists of a wreath of golden roses & a crown atop the letter "E", all on a blue field
[DOC] [TLE] Royal Standard of the United Kingdom - Wikipedia [PAR] The Royal Standard of the United Kingdom is the flag used by Elizabeth II in her 
capacity as ... banner of arms with a blue disc containing a wreath of gold roses 
encircling a crowned letter 'E', (for 'Elizabeth'), superimposed upon it (the 
Personal Flag of Queen Elizabeth II).