Is it permissible to account for what was spent on each son in the division of inheritance, and is it permissible for the sister to build without the permission of her partner, and is it permissible for her to prevent him from disposing of his share?

If the father divided the land between his daughter and son during his lifetime, and the mother approved, and the children took possession of the land through lawful acquisition (ḥiyāzah shar‘iyyah), then the gift (hibah) is valid, and equality in giving must be observed. If the daughter's share exceeds the value of the son's apartment, then an offset (muqāṣṣah) is required. However, if the division occurred during a death illness (maraḍ al-mawt) or if the land was not possessed until after the father's death, then the gift is not binding, and the land shall be divided according to the prescribed inheritance law (mīrāth shar‘ī). What the father spent on his children, if it was necessary for the son and he was unable to provide it himself, then that falls under obligatory maintenance (nafaqah wājibah). Otherwise, the father must equalize the other children with what he gave to one of them. The sister building on shared land without her brother's permission is not permissible. The sister's condition of not selling to a stranger is permissible if she intends to buy (right of pre-emption - ḥaqq ash-shuf‘ah), otherwise, she has no right to impose this unless the brother agrees out of kindness (iḥsān).