Do the maternal nephews of the deceased inherit, and what is the distribution of the inheritance between the wife and the maternal sister?

If the deceased leaves behind only a wife and a maternal sister, the inheritance is divided between them as follows: The wife receives one-fourth as her prescribed share, due to the absence of a direct descendant. The maternal sister receives one-sixth as her prescribed share, and then takes the remainder by way of return (radd). The children of the maternal brother receive nothing. The inheritance is divided into twelve shares: the wife takes three shares, and the maternal sister takes nine shares (two as her prescribed share and the remainder by way of return).