Beatrice can't use the title Countess Mapeli Mozzi as foreign titles of nobility cannot be officially used or recognized in the UK by British citizens, following a 1932 Royal Warrant. She is a Princess by Royal Blood and could be simply called Princess Beatrice, dropping 'of York'. Though since her marriage she been styled by the Court Circular as: Her Royal Highness Princess Beatrice, Mrs Edoardo Mapelli Mozzi