Spoiler alert! If you plan on attending Madonna's Dec. 22 Scottish nuptials to Guy Ritchie and want to be surprised by the bride's attire, read no further! According to the material mom's fan club Web site, she plans to walk down the isle donning a priceless diamond-encrusted tiara that belonged to the late Princess Grace of Monaco. However, just to prove she's no princess herself, Madonna also reportedly will wear a pair of diamond-studded cowboy boots during the ceremony. Her dress has been designed by Paul McCartney's daughter Stella.