Husband
At the time of the wife's death, the ratio of legacy due to the husband is half in case that the deceased wife has not a son or daughter. He is entitled to half even if the woman has only heirs at lateral branch, as brother, or uncle. A one-fourth goes to the husband if the wife has left behind a son or daughter, or if her direct ancestor, i.e., parents are still alive. The share of a boy is always twice that of a daughter

Wife
At the death of the husband, the wife is entitled to the one-fourth of the legacy if the husband has not left behind a son or daughter from her of from someone else. Her right is also one-fourth if the husband's parents are still alive among the heirs. One-eighth is paid if the wife has a son or daughter from the husband. One-eighth is the right of the children in compliance with the prescribed proportions. (boy: girl = 2 : 1)

The inheritance right of the spouses exists in two cases. 1. If they were married according to Islamic rules. 2. If the marriage has taken place, i.e., it is a marriage that has been perfected by sexual intercourse. If the death takes place during the divorce process, the right of inheritance lasts as long as the divorce can be restored and settled, i.e., the husband did not declare the divorce for the third time and the ‘Idda (mandatory wait, i.e., 3 menstruation) was not fulfilled. If the divorce has taken place and the ‘Idda has been fulfilled, all further inheritance relations of the parties will be terminated among each other, they cannot be each other’s heirs or legatees. This does not affect the rights and obligations that the parties agreed upon at the time of the divorce, which is a completely different contract, not the subject of inheritance. These latter obligations are passed on to the heirs.

Father and mother
The parents have the right either to the one-sixth or one-third of the estate. It depends on whether their deceased child has a direct descendant.

1. example

The father, mother, wife and two sons are left behind.

The smallest common multiple of the denominators is 24. We see a breakdown of that in the table.
Since we are counting two sons, this must be multiplied by two, so 48. After that, as before, the number of shares of the heirs in the table is multiplied by 2.

After correction:
the number of shares of the father is 2 x 4 = 8
the number of shares of the mother is 2 x 4 = 8
the number of shares of the wife is 2 x 3 = 6
the number of shares of the two sons is 2 x 13 = 26, 13 each

2. example

The father, two wives, and a daughter are left behind.
The father has one-sixth, the two wives one-eighth, and the daughter the half. What remains must be distributed among the lateral branch of heirs.

3. example

A woman dies and leaves behind a father, a daughter and her husband. In this case, the father is obligatorily entitled to one-sixth, the daughter to half, and the husband to one-fourth. If lateral heirs remain, the remainder can be distributed among them.

The smallest common multiple is 12. If I add the calculated inheritance ratios based on that, then 2/12 + 6/12 + 3/12 = 11/12. From this, it appears that one excess share will be remained, that will be given to lateral heirs, and 11 shares will be distributed among the heirs in a ratio of 3 : 6 : 2.

Mandatory proportion of grandparents
In terms of inheritance a grandparent is considered the person whose bloodline is connected in a straight line with the deceased. If the deceased leaves a parent behind, the grandparents are left out of the inheritance. If there are no parents, the grandparents are reclassified as parents and one-sixth are due to them.