Q.What is the proper role for grandparents when their 32-year-old daughter neglects her own daughter, now 12? The child's parents were 20 when they married; the father just walked away when the child was a year old, never giving my daughter a reason for his leaving.

He saw the child perhaps six times before she was 6 years old and hasn't seen her since or even called her on her birthday or Christmas.

My daughter is a classic case of "arrested development" and pursues a hedonistic life style. She lives on a teen-aged level and dresses as she did then -- blue jeans, T-shirts (mostly with logos) and flannel shirts, even to work.

She has moved in and out of our home, with the child, at least 20 times. When they were here together, my daughter's contact with her child was a brutal yell session in the mornings when they were preparing for work and school. On Saturdays and Sundays my daughter would arise at noon or later, occasionally taking the child to a child-oriented activity but usually to the taverns she haunted at night. My granddaughter sees all.

Two years ago I asked my daughter to find an apartment for the two of them, believing she would assume her responsibilities if I weren't so available. Instead she left the child unsupervised.

They then moved into a house with my daughter's boyfriend (a musician), and another man when my granddaughter was 11. I try not to be an alarmist but the lack of supervision caused me grave concern. My granddaughter usually called me several times a day so I knew we had a problem, but I hoped it would right itself.

Finally my husband and I asked our daughter to let her child live with us, which she did. The child said she had been thinking of this herself because "Mommy's never home, and you are."

Just two weeks ago my daughter finally told us she smokes pot about three times a week, but hasn't used cocaine for about a year. Even though my granddaughter had told me the odor of marijuana often hung heavy in the air and that her mother had used the mirror I had given her to arrange her cocaine with a razor blade, this admission devastated me. My daughter had previously lied about it.

It is extremely difficult to acknowledge that your daughter, reared by you, taught by you, is indeed neglecting her child. I can't conceive of anyone having a child and not meeting that child's needs. Obviously, I was unable to impart this philosophy to my daughter.

She does have some positives, but it's hard to concentrate on them. She's had the same job for several years, for instance (although she doesn't pay her bills).

We are all currently going to therapy, because I need guidance in dealing with the child's anger.

This has helped but the focus is on the child. My daughter's problem is not being addressed.

Nor can I find a proper direction for myself. How can I fulfill my role, give my granddaughter her chance and ideally help my daughter find out who she is and what is her role? A.A. Can anything hurt a parent A. more than to watch her child grow awry? The anger, the guilt, the resentment and depression you feel must be deep -- and yet, like any mother, it is your own child -- not your grandchild or yourself -- whom you most ache to help.

To do it you need a realistic view of the past, the present and the possibilities.

Even if your daughter has quit cocaine, she's still in trouble. A woman who smokes pot three times a week can be said, without too great an exaggeration, to be addicted. Pot's most damaging known ingredient, THC, is not only 25 times stronger than it was a decade ago but it has a half-life of a week. She is always under its effect, day in, day out, with her perceptions foggy, her motivation low, her temper touchy. On top of that, she goes to bars so often she may have a drinking problem. How could she meet her child's needs?

Stop blaming yourself -- and her -- for the situation and thank the heavens that she found the courage to tell you the truth.

The less judgmental you are and the less you think about the yesterdays, the more you can reach her, but neither you nor a therapist will get far as long as her body and mind are bent by drugs.

Even with your forward-looking support, she won't be strong enough to quit alone. She needs to enter a detoxification program, if possible, and to join Alcoholics Anonymous, which is open to drug users, too. Here other members will encourage her and steer her toward healthier friendships. She may not turn out to be the most lovable mother (or daughter) in the world, but she'll be more responsible.

You also want to read about the problem thoroughly. Getting Tough on Gateway Drugs by Dr. Robert L. DuPont Jr. (American Psychiatric Press; $16.95) will show you how she got there so you can explain it to your granddaughter. It's important for her to know that drugs, and not a lack of love, have made her mother so unreliable. Addiction is as much an illness as cancer.

Your granddaughter will profit by Alateen meetings as well as Children of Alcoholics -- the newer, most helpful offshoot of AA for people of all ages.

Al-Anon, or a group just for parents, should help you and your husband learn how to deal with your daughter. A therapist is needed, too, for you're taking on a big job with a lot of freight, but the outcome should be brighter. The odds have improved since the '60s. Drugs are still a big problem but today, at least, parents are backed by solid research when they tell children that alcohol, marijuana and cocaine are dangerous and addictive.

With patience your daughter will get the message, too. Just keep loving her and keep showing it by caring for the child. Never have either needed you so much.