What is the religious ruling concerning a mother who squandered the money of her minor children, and how should the son act in this situation?

Bequest (al-i'ṣā') is the authorization of a person to manage their wealth and the affairs of their children after their death. The hand of the guardian (waṣī) over the deceased's wealth is a hand of trust (yad amānah), so they are not liable for any damage to the wealth without transgression or negligence. If those under guardianship dispute with the guardian concerning what was spent, the guardian's word is accepted with their oath, unless they were extravagant. Therefore, the mother's statement is accepted with her oath, according to the preponderant opinion, that she spent the money on her children; if she swears, she is believed. If the adults pardon her from the oath, it is better. As for the minors, their matter is suspended until they reach puberty and maturity. However, if the guardian has spent extravagantly, then the word is that of those under guardianship, because the guardian is liable due to their negligence. It is advised to be lenient with the mother regarding what has passed and to be cautious regarding what is to come, out of filial piety and kindness towards her.