Praise be to Allah.
If one parent has died, or both parents, 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):
“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”
For example, if we assume that after shrouding the deceased, paying off his debts and fulfilling his bequests, the amount he left is 9000 for example, then the daughter will have 1000 and each of the males will have twice that, namely 2000.
But if there are other heirs as well as the children, such as the father of the deceased, or his mother or grandfather or grandmother, then each of them must be given their share, and the rest divided among the sons and daughter in the manner mentioned above.
Note: If one spouse died before the other, then the living spouse inherits from the deceased. In the case asked about here, the share of the husband if his wife dies before him is one-quarter. The wife’s share if her husband dies before her is one-eighth.
For the children who are left, the estate should be divided giving each male the share of two females, as mentioned above, after the surviving spouse has taken his or her share.