She died leaving behind a mother, four brothers, and two sisters, and bequeathed a third [of her estate]?

The mother's share is one-sixth due to the plurality of siblings, and the remainder of the estate is divided amongst them with the male receiving twice the share of the female if they are full siblings or siblings from the father's side. Full siblings preclude siblings from the father's side. If the males are siblings from the father's side and the two sisters are full siblings, then they receive two-thirds, and the remainder is for the siblings from the father's side equally. The bequest is taken from the principal of the estate, provided it is not for an heir. The evidence for this is the saying of Allah the Most High: "But if he has brothers [or sisters], for his mother is the sixth, after any bequest he [may have] made or debt." And His saying: "They request from you a [legal] ruling. Say, "Allah gives you a ruling concerning al-kalalah [inheritance by siblings or half-siblings]. If a man dies and he has no child but only a sister, for her is half of what he leaves." And the saying of the Prophet, peace and blessings be upon him: "Give the prescribed shares to those who are entitled to them, and what remains goes to the nearest male relative." And his saying: "There is no bequest for an heir." The matter of inheritance is serious and complex, and it is not sufficient to rely on a fatwa (definition). Rather, it must be referred to the Sharia (definition) courts to verify the existence of other heirs, bequests, or debts.