Is it obligatory to deduct the value of half a feddan from the inheritance of the younger brother, which his mother spent on him before her death, knowing that she has another son and a daughter?

Favoring some children in a gift is forbidden, and the giver must retract this unjust gift or give to all to achieve justice, unless there is a legitimate reason. If the giver dies without retracting their gift, the majority of scholars hold that it should not be revoked, and the remaining heirs have no right to reclaim it from the recipient. Therefore, the remaining heirs have no right to demand anything that their mother spent on their brother to the exclusion of themselves after the mother's death.