Mumbai, November 17 Tagging her as her ‘first child’, filmmaker-choreographer Farah Khan says she discovered Malaika Arora first and then Deepika Padukone. Speaking about her own experience of shooting on a moving train for the song ‘Chaiyya chaiyya’, ‘Jhalak Dikhla Jaa’, judge Malaika said: “I remember how challenging it is to dance on a moving…