Is a mother entitled to demand her 12-year-old son's money if the father refuses to give her the money or give it to the son to buy his necessities?

The mother does not have the right to demand the son's money from his father. Guardianship belongs to the father, and he is responsible for managing the money in a way that benefits the son and spending with moderation, without extravagance or stinginess. The mother can demand that the father spend on the son according to what is customary, and she can also ask him for money for herself if she is in need, for parents are allowed to take from their child's wealth what they need.