Q. I'm a 30-year-old single woman who has been very involved in the lives of fraternal twin boys, born to my closest friends 2 1/2 years ago.

Both boys are in speech therapy because of severely delayed speech, but one child is more verbal, more extroverted than the other, who whines a lot, throws tantrums and hits people, including his twin. Even if he is punished, he later resumes the behavior that got him into trouble.

I suggested to the parents that the "hitter" is frustrated because he is always in his brother's shadow, and that the boys need more individualized attention.

I am willing to take each child out separately to help him develop his own identity but the father is adamantly against it. He feels it will be too stressful for the children to be apart.

How do I let my friends know that I only want what's best for the children?

A. You'll be a good deal more effective if you try to help your friends on their own terms and keep your opinions to yourself.

What seems like sound advice to you probably seems like plain old interference to them. They welcome the thoughtful judgments of friends and relatives, but only as long as they're complimentary.

This is understandable. Parents -- and especially the parents of twins -- have the most demanding, creative job in the world. They solve one problem, and another one crops up, time after time, until it can seem like they never do anything right. The more other people second-guess their solutions, the more their self-confidence takes a nose dive.

Your friends need your love and support -- and your trust -- instead of your criticism. Although they may go off the track sometimes, they still understand their children better than anyone else. Certainly such early intervention to correct their sons' delayed speech -- a fairly common problem for twins -- tells you that they are very responsive parents.

If they think their sons might be upset if they're apart, they're probably right.

You can strengthen the boys' identities in other ways. Like all twins, they want to be treated as individuals; to have their differences noticed and appreciated more than their similarities; to be referred to by name, not as "the twins." You can do all of this for them no matter where you are, or whether you're with one child or two, although it helps if you have a clear understanding of twinships -- one of the most misunderstood relationships of all.

As Pamela Patrick Novotny explains in "The Joy of Twins" (Crown; $19.95), some identical twins do have a secret language and a terribly close affinity, and a very few may have ESP, but even "identicals" have a number of differences, and fraternal twins have many, many more. Researchers now find that these twins interact much like any two siblings who are born less than two years apart.

Whether twins are identical or fraternal, one of them may dominate in certain situations and at certain ages, but they usually pass the scepter back and forth several times as they grow up. This dominance isn't a big problem, even if one child is consistently submissive. That simply tells you he's more of a follower by nature and the world could do with a few more like him.

When a child consistently rebels, however -- as this cantankerous twin is doing -- you have to look at the broader picture, starting, as always, with the child's physical health. Some children lash out in reaction to a favorite food -- milk is the biggest offender -- and may turn angelic if it's taken out of their diet. "Detecting Your Hidden Allergies" by William Crook (Professional Books; $11.95) would teach the parents how to test their son for food sensitivities, so they could rule out that cause.

His poor speech is the more likely problem, for any child is frustrated if he can't be understood, especially since adults must find it easier to listen to his brother.

You can help the slow talker by reading to him more, talking with him more, repeating what he says -- but a little more distinctly -- and by playing "I spy something ... BLUE!," where clear speech is important, but the game matters more.

Sit on the floor, put your face right up to his and enunciate clearly, so he can see how the tongue works when you say "blue." You can play the game with both boys, and still give more attention to the less-verbal child, without turning yourself into a speech therapist.

You might also give the parents a little time off by offering to move in for a weekend. This would give them the chance to get away and if you hire a young teen-ager to help you at the playground, you could give the difficult child still more attention. It may not make a big difference, but as someone once said, "The unlovable child is the one most in need of love."

You clearly have a lot of love to give, and if you can't spend so much on these boys, there are a lot of boarder babies out there, just waiting for someone like you.

Questions may be sent to P.O. Box 15310, Washington, D.C. 20003.