How is the estate of a woman who died, leaving behind a mother, two full sisters, and a husband, divided?

The mother receives one-sixth due to the presence of the two sisters. The two sisters receive two-thirds. The husband receives one-half. These shares exceed the inheritance, and this situation is called "Al-Awl" (the proportional reduction of shares), so the share of each heir is decreased. The inheritance is divided into eight parts: the mother gets one part, the two sisters get four parts, and the husband gets three parts.