Is the money the mother receives lawful or unlawful, given that she did not submit a sick leave request and attendance and departure are signed for her while she is absent from work?

If the sector head is authorized to grant permission and has the authority to sign, then there is no harm in receiving the salary. However, if he is not authorized and he favored her with the signature, then she is not allowed to take the salary unless the rightful person gives it to her.