Is it permissible to reconsider the division of inheritance after the death of the father and brother, knowing that the father secretly bequeathed half of his dwelling to the deceased and deprived the rest of the heirs? And what is the ruling on the actions of the father and brother?

It is forbidden to discriminate between children in gifts due to the injustice and oppression it entails. If a father singles out one of his children for a gift and then dies before equalizing them, the one who received the excess must return it to the estate to be divided among all heirs. If he does not do so, it will be deducted from his share.