If we were talking about a stranger stealing that money from her I would agree with you, because we must do what we can to protect our money, however it was her own son who did this, meaning that a person she trusted, broke that trust by stealing from her own mother, and while the amount was small, what can be more low than stealing from your own mother? So I would not blame her at all for this situation as it is clear that it is the son that is at fault here.
This is very simple, if a child goes off the Rails like that you have to give him some discipline, there is no other way, a person cannot do that to his own Mother , there he has to take things and tie his pants and educate him, because at that moment he won't. did it to his own mother, and later more children will have the audacity to do it to another person and that Becomes a problem that is almost very difficult to solve, because sometimes they are Raised with that way of thinking and doing things so much that You can put him in a reformatory for minors, that is something that can happen, of course it is something that is not desired but if it is not corrected in time these things can happen like that, and that is a Shame.