Are the fatwas that prohibit taking a piece of candy from a child, or giving his outgrown clothes to his brother, sound?

A father's disposal of his children's inherited clothes is permissible, as providing for children is obligatory upon the father. Providing a replacement for the son whose clothes were taken is necessary to fulfill the obligatory provision. It is permissible for a father to take from his son's money without his permission what he needs for maintenance. This is supported by the hadith of Abu Bakr when he took a piece of bread from his son Abd al-Rahman and gave it as charity. In addition, a father has the right to reclaim what he has gifted to his son. As for a child gifting something to others, it is not valid due to his not having reached maturity.