167. Two Mourners
26:15 Two people with equal priority in saying Kaddish who are equally worthy of leading the service should draw lots. The first says up to Ashrei/U’va l’Tziyon and then the second takes over. If one is unable to serve as shaliach tzibbur, or if the congregation finds one of them objectionable, with the result that the other one led the service, the one who led the service did not give up his rights to say Kaddish by doing so. Nevertheless, it would be appropriate for him to give the other mourner Kaddish to say. This all the more so in the case of a minor (who cannot lead the service and can only say Kaddish).
26:16 One who is in mourning for both his father and his mother does not have higher priority in leading the service or saying Kaddish than anyone else, since a single recitation of Kaddish covers both parents.