How is the estate of a deceased person divided among a mother, three sons, and a daughter, taking into account the deceased's will for a prior distribution of the inheritance to some of the sons and the daughter years before his death, and is this prior distribution permissible?

If the deceased leaves behind only the mother, sons, and a daughter, the mother receives one-sixth due to the presence of a lineal descendant (heir). The remaining portion is distributed among the sons and the daughter by ta'sib (residuary heirship), with the male receiving the share of two females. A gift to the sons without the daughter, without a legitimate شرعي justification, is void and must be returned even after the death of the donor. What the father wrote for his daughter but she did not receive until his death is considered a bequest to an heir and is not valid unless the other heirs consent. Everything must be returned to the estate, and the matter should be taken to the Sharia court for division, as inheritance issues are serious and complex and require investigation by the Sharia courts.