How is the inheritance divided among the wife, the full sister, and the full brother's son?

If the deceased leaves behind only a wife, a full sister, and a full brother's son, then the wife receives one-fourth as her prescribed share due to the absence of any lineal descendants. The full sister receives one-half as her prescribed share. The remainder goes to the full brother's son by way of residuary inheritance ('asabah). The estate is divided into four shares: one share for the wife, two shares for the full sister, and one share for the full brother's son.