Is it obligatory to include the married daughter in the ownership of the company owned by the parents, knowing that there are other properties and that the purpose is not division but tax transactions?

A Muslim must be just between his sons and daughters in giving gifts, and not prefer some over others except for a legitimate reason, such as dire need or illness. If you want to include your sons in the company and give them real shares, you must include your daughter with them, because of the Prophet, peace and blessings be upon him, who said: "Fear Allah and be just among your children," and his saying: "Be equitable among your children in giving; if I were to prefer anyone, I would prefer women." However, if the inclusion of children in the company is fictitious for the purpose of tax evasion, then it is not necessary to extend it to all children, bearing in mind that tax evasion has permissible and impermissible cases. Also, fictitious partnership for some children without others may lead to depriving those who were not included, and measures must be taken to ensure they are not deprived.