What is the share of the heirs of a deceased woman who has neither ascendants nor descendants, but has nephews and nieces (sons and daughters of brothers and sisters), given that there is a will stating that "she bequeathed all she owns to her sister's son and daughter"? And what is the ruling on the sister's son taking a third of the inheritance along with his share or without it, and are they (the beneficiaries of the will) sinful if they keep the inheritance, and what is the ruling on the heirs waiving their right?

The nephew and niece (sister's son and daughter) are not heirs but are considered Dhawi al-Arham (relatives through the mother's side or distant relatives who are not primary heirs). A bequest (wasiyyah) to them is valid.

If the deceased bequeathed all her wealth to her nephew (sister's son) and niece (sister's daughter), and left no heirs except her two paternal nephews (full brother's sons), then:

1. If the two heirs (the paternal nephews) approve the bequest, and they are adult and of sound mind, then the nephew and niece (sister's son and daughter) will inherit the estate equally, or as specified in the bequest.

2. If the heirs reject the bequest, the nephew and niece (sister's son and daughter) will receive only one-third of the estate, equally divided between them. The two paternal nephews (full brother's sons) will receive the remainder by ta'sib (agnatic inheritance). The estate will then be divided into six shares: one share for the nephew (sister's son), one share for the niece (sister's daughter), and two shares for each paternal nephew (full brother's son).

It is not permissible for the nephew and niece (sister's son and daughter) to take the estate forcibly if the heirs refuse to approve the bequest.

Matters concerning inheritances must be referred to the Sharia courts.