He died and left behind a full sister.

If the deceased leaves no heir except a full sister, she inherits half of the estate as a fard (prescribed share), based on the Almighty's saying: "If a man dies, leaving no child but a sister, she shall have half of what he leaves." She then takes the remaining half by way of radd (return), based on the Prophet's (peace be upon him) saying: "Whoever leaves behind wealth, it is for his heirs." Thus, she inherits the entire estate.

Inheritance matters are serious and complex, and it is not sufficient to rely merely on a fatwa. Rather, they must be referred to Sharia courts for investigation and to ensure that there are no other heirs, wills, debts, or rights that take precedence over the heirs' entitlement.