Q. Our 36-year-old daughter is in the second year of her second marriage, and it's going pretty well despite fairly drastic differences in their ages, backgrounds and cultural preferences.

He is a retired serviceman who is nine years older than she is, works long hours and has a long commute. She works at home and therefore is the one who watches his 14-year-old son as well as her own 11-year-old son and 9-year-old daughter. All go to different schools, have different levels of accomplishments and are involved in different sports, so she ferries them to their many activities.

Her stepson is her real concern. His mother, with whom he lives part time, buys him whatever he wants and offers little in the way of guidance and long-term goals. My daughter has told me many times - and possibly told him - that he is lazy, but I think he is displaying some passive resistance. She wants him to get off of his duff and do better in school and in sports, but his father, who did more surfing in high school than anything else, is annoyed by this approach and thinks she should back off.

At this point my daughter is looking for help because she thinks that she may be triangulating the situation and taking it in several dangerous directions. I urged her to find a therapist (though her husband won't have anything to do with that) to see whether her tendencies to be a supermom could be getting in the way of her relationships.

A. It's okay for a parent or stepparent to be ambitious for herself, but she doesn't have the right to be ambitious for anyone else.

Your daughter also shouldn't tell her stepson that he is lazy, because children are never lazy (and neither, in fact, are grown-ups). The boy may act lazy because he is passively resisting your daughter's advice, as you suggest, but he also may act lazy because he has a low-grade chronic illness, even if it hasn't been diagnosed. Or he's going through a growth spurt that makes him need more sleep than usual. He also may be doing poorly in school and in sports because he has learning disabilities or because he is weak in the areas where your daughter wants him to excel, which is unrealistic. No one is equally good in everything.

More likely, though, the boy has just given up. That's often the case when a child is sad or angry or pushed too much in the wrong direction or in the wrong way. Your daughter would encourage her stepson far more if she commended him when he did good work, however small and insignificant it was, instead of chastising him when he made a mistake. Parents are much more effective when they notice a child's positive behavior instead of his negative behavior.

If your daughter tries this approach with her stepson, he should start acting better in two to three weeks. If he doesn't, the two of them should see an experienced family therapist. Sometimes it takes an outsider to ask them the kind of provocative questions they dare not ask each other and also to teach them how to say what they think without being rude or falling into a conversational ditch. Teenagers are often too shy, too confused or too socially inept to explain themselves well, especially the children of divorce.

If this boy is still shaken by the finality of his parents' divorce and by the way it tore his safety net apart, it may take five to seven years before he can truly trust them again or to form a strong bond with a stepparent. "Why bother?" he says to himself. "If my first family fell apart, this one will probably fall apart, too."

To help your daughter establish a better relationship with her stepson, you might give her these two fine books: "The Myth of Laziness" by Mel Levine (Simon & Schuster, 2003, $16) and "Keeping Your Kids Out Front Without Kicking Them From Behind: How to Nurture High-Achieving Athletes, Scholars, and Performing Artists" by Ian Tofer and Theresa Foy DiGeronimo (Jossey-Bass, 2000, $29).

If she follows the advice in the first book, she'll realize that her stepson must find the learning style that's right for him before he can go forward. If she follows the advice in the second book, she'll know that he'll achieve success only when he tries to reach his own goals, rather than hers.

Kelly will be online at www.washingtonpost.com/discussions to take questions Thursday at noon. Or send them to advice@margueritekelly.com .