Q: Our daughter — our only child — is in her mid-30s and she and her husband are successful professionals and parents of a 3-year-old daughter and a 1-year-old son. They are the delight and the joy of their Grannie.

The parents think that they’re doing a good job because they don’t hit their children, but they do scream at their little girl, they demean her and they can be extremely hateful to her, even though she is loving, smart and athletic. She is, however, a challenging child who doesn’t always listen, who can be defiant at times and who has always had trouble falling asleep. Her father reacts to it by staying with her for more than an hour at night or by forcing her back to bed while he boils with anger.

If my daughter sees her child misbehave, she says, ”You’ll never have any friends.” And she yelled at her when the child’s attention waned when she was playing soccer. “You’re just too little to play!” she said. And then they threw her into the car and drove her home — screaming all the way — so she could take a nap.

Sometimes they also berate the baby if he disobeys, but he is much more easygoing than the older child and goes to sleep readily so they usually make much of his sweetness. I guess that’s why his big sister slips into baby talk sometimes.

I have spoken up at times — and occasionally said more than I should have — because I feel a need to protect the children, but my daughter can be vindictive. If I say too much, I’m afraid that she will keep them away from me.

Our daughter has also said very abusive things to her father and me and yet she was so caring and compassionate as a child. I don’t know what went wrong. We have offered to pay for her therapy — there is mental illness in the family — but she says that she’s too busy to go.

What else can I do?

A: When parents are drowning they need a life raft — and these parents are in water up to their chinny-chin-chins.

You didn’t turn your daughter into such a scold, however, and she probably didn’t inherit bad mental health genes either. Instead, she and her husband sound like two overworked, overwrought parents who are overwhelmed because of all that they don’t know.

People who spend a great deal of time being good at their jobs often forget that parenthood is a job, too — and an art and a craft — and that it is the most important job they’ll ever have. If they want to do it well, they have to learn about many things, including child development.

It doesn’t matter whether parents are lawyers, doctors or in the trades, their children are still children who take twice as long to go half as far as they do. Not only that, they will expect to be congratulated for being so fast. And they should be. Children not only learn to walk and talk and feed and dress themselves in the first three years, but they learn how to play with others, to negotiate with them and to settle squabbles in a civilized way.

You can help your daughter and her husband appreciate their children more if you baby the parents a bit. Begin by bringing dinner to the family every Thursday — that wretched day when they know that the week is falling apart again. A basket packed with homemade comfort food for the parents, rather than chicken nuggets for the children, will soothe their souls, especially if you’re the one who sets the table, cleans up afterwards and puts the babies to bed.

You may be tempted to tell your daughter that a 3-year-old is too young to be put on a soccer team, which he is, but she really needs you to notice the things she does right. Compliments make parents — and children — behave much better than criticism.

Also give them copies of three books: “Your One-Year-Old” and “Your Three-Year-Old” both written by Louise Bates Ames and Frances L. Ilg (Dell; $16) so they will know what to expect at these ages and “How to Talk So Kids Will Listen and Listen So Kids Will Talk” by Adele Faber and Elaine Mazlish (Scribner; $16) so they’ll know what to say.

Once this couple feels cosseted, send them tickets to a parenting class so they’ll learn when (and how) to discipline their children. And to make sure they’ll go, promise to babysit the children and to do the laundry when they’re at class.

Questions? Send them to advice@margueritekelly.com.