Are the brothers entitled to demand the division of what the grandmother gifted to her brother during her father's lifetime and with everyone's approval?

Scholars have differed regarding the ruling on equitable distribution in giving gifts to grandchildren. The Hanbalis are of the opinion that equitable distribution among them is obligatory, just as it is among direct children, while the Shafi'is consider it recommendable. There is also a view among the Hanbalis that equitable distribution among grandchildren is not obligatory, and this is the relied-upon opinion (al-mufta bihi). Therefore, there is no sin upon the grandmother.