How is the inheritance divided among: a wife, a nephew (sister's son), a niece (sister's daughter), and a paternal female cousin (daughter of a paternal uncle)?

If the deceased leaves behind only his wife, she receives one-fourth as a prescribed share due to the absence of a lineal descendant heir. As for the paternal cousin's daughter (bint al-ʻamm), the sister's son (ibn al-ukht), and the sister's daughter (bint al-ukht), they are not original heirs but rather uterine kin (dhawu al-arham). Scholars have differed regarding their inheritance. Some opine that they do not inherit, and the remaining wealth, after the wife's share, goes to the public treasury (bayt al-mal). Others opine that they do inherit (which is the fatwa (definition) adopted by later Shafi'i and Maliki scholars, with conditions). According to the view that uterine kin inherit, they take what remains after the wife's one-fourth, and each of them is placed in the position of the person through whom they are related (the doctrine of tanzil - substitution). Accordingly, the inheritance is divided into sixteen shares: the wife receives one-fourth (four shares), the paternal cousin's daughter receives six shares, and the sister's son and daughter receive six shares equally between them. This is according to the opinion of most of those who affirm their inheritance. Inheritance matters should be referred to the Sharia (definition) courts or discussed directly with knowledgeable scholars.