Who inherits a deceased, unmarried woman whose parents have passed away, and who has nephews from a deceased brother and nieces from a deceased sister, and how are the shares distributed among them?

If a woman dies and leaves behind her brother's sons and her sister's sons, then her inheritance is divided among her brother's sons only, without her sister's sons, because they are 'asabah (agnate heirs) by themselves and closer to her. As for the sister's sons, they are from among the dhawu al-arham (relatives by blood, but not agnates) and do not inherit when 'asabah are present. The matter of inheritances must be referred to the Sharia courts for consideration and investigation.