For 17 years, Kate and Gerry McCann have endured the unimaginable pain of living without their eldest daughter, Madeleine. RadarOnline.com can reveal she was just three years old when she disappeared from their holiday apartment in Praia da Luz, Portugal, on May 3, 2007. The McCanns had been dining at a nearby restaurant with friends, only to return to the devastating discovery that their daughter was gone. Since that fateful night, the McCanns have tirelessly campaigned to find Madeleine, who would now be 20 years old. In a recent development, Christian Brueckner, the main suspect in her disa…