Praise be to Allaah.
If one parent has died, or both parents have, and they have no heirs except four sons and one daughter, then the estate should be divided on the basis that each male takes the share of two females, i.e. the daughter will have one share and each of the sons will have two shares. So the estate should be divided into nine parts, of which the daughter will have one share and the eight remaining shares will be given to the four sons, each of them taking two shares. This should be done after taking out the expenses of preparing and shrouding the deceased, and paying off any dues he owed to Allaah or debts he owed to other people, and after fulfilling his bequests if he left any such instructions before he died.
The evidence for that is the verse in which Allaah says (interpretation of the meaning):
Al-Nisa’ 4:11 : “Allaah commands you as regards your children’s (inheritance): to the male, a portion equal to that of two females; … (The distribution in all cases is) after the payment of legacies he may have bequeathed or debts”