She had one brother , Prince Charles Edward , Duke of Albany ( 1884 â `` 1954 ) who was reigning Duke of Saxe-Coburg and Gotha ( 1900 â `` 1918 ) . She had one brother , Prince Charles Edward , Duke of Albany ( 1884 â `` 1954 ) and later reigning Duke of Saxe-Coburg and Gotha ( 1900 â `` 1918 ) .