Like the philosophical argument that sometimes not making a decision is in fact a decision in itself; is it possible (we are asking here) that at times the best thing a well mannered mother can do is nothing at all? Certainly there will be times when a mother does not care for her young child's choice of smarty mouthed friend. Or think that her child is not spending his free time is a worthwhile way. Or wish that he had thought longer and differently about a certain homework answer. In these and practically any other situation a modern mother has the ability to 'do something' to change these things. She can attempt to 'manage' the friendship by making her child unavailable or pointing out the flaws in his choice of companions (N.B. often the stamp of parental disapproval is all a child need to find someone truly cool). She can enroll him in more activities so his free time is not "wasted" in her opinion. And she can reasonably and calmly sit down with her child and explain at length why he should re-do his homework to produce the answer she thinks is best.
Sure it may be exhausting but what is the alternative? Trusting that her child will eventually figure out what he needs in a friend? Letting her child come to her with a proposal of how he would like to spend his free time? Letting him get a bad grade on a homework assignment? But then what? By that time he may not be in the popular crowd or have missed the opportunity to play ice hockey or not gotten into that ivy league school. At which point his life will be over. Or, maybe, let's look on the bright side for a moment, maybe he will emerge a confident, capable, happy person who did not spend his youth being molded into someone else's idea of a successful person. Plus, maybe the well mannered modern mother can relax for a while and take comfort in believing that doing nothing is really doing something after all. *
*This advice does not apply to truly dangerous or destructive behavior. In such cases a parent should absolutely get involved and help her/his child in any way possible.