How are male children to be involved in the business they worked in without a known share, taking into consideration the number of years each of them worked? And must they be compensated for previous years? What about the daughters?

It is not permissible for a father to favor some of his children over others in giving gifts, unless there is a legitimate Shariah reason, such as singling out a child who has assisted him in his work or business. In this case, the amount given must be proportionate to the value of the assistance provided, taking into account the number of years each child worked and compensating them by granting them a known share of the business's assets. As for daughters, he is not obligated to give them what he gave to the males, because what was given to the males was in return for their work and a reward for their efforts. Neither the daughters nor the sons have a share in the business's assets as long as the father is alive. Rather, after his death, the inheritance is distributed according to Islamic law.