Q. When I was pregnant I gave up smoking and drinking, ate all the right foods, exercised and only gained about 12 pounds.

We have a very happy baby -- the doctor says he's "obnoxiously healthy" -- who is 8 months old.

I have four questions:

1.) Is there a certain age when it is generally expected to stop breast-feeding? The baby and I really enjoy it, but both my husband and my mother-in-law think I should stop. I don't want my son to be a "Mama's boy," nor do I want him to walk over and pull out my breast in public when he's 2 years old. I am supplementing his feeding with oatmeal, fruit, etc.

2.) My husband occasionally smokes marijuana. Would a few puffs hurt the baby?

3.) Are there any guidelines to tell a mother what she should or should not eat or drink if she is breast-feeding? I had quite a bit of wine during some recent holidays. Could too much hurt him?

4.) I have gained 25 pounds since the baby was born. Is this normal? Some of this is from lack of exercise. I'm not trying to make excuses, but a friend said this gain is common, especially among C-section mothers. I also haven't gone back to smoking.

A. There is one underlying thread in your four questions. You're doubting your instincts in every case. Please don't. You know your baby and yourself better than anyone else. The bond between you is almost mystical. If you have any doubts about anything -- no matter what in-laws, friends, doctors (and advice columnists) tell you -- listen to your own heart.

Should you stop breast-feeding? Why? If you and your child both enjoy it, he should be breast-fed. That's one reason he's so healthy.

If you give him milk from a cup with increasing frequency he will be weaned gently by his first birthday, while an abrupt switch to a bottle now will present another weaning problem in a year or two.

Or you can just give him juice and water from a cup and still continue to nurse. If he does become a 2-year-old who would make a grab to be fed in public, you either would let him know that you were embarrassed, or you would stop nursing.

And will all this nursing turn your son into a Mama's boy? of course not; it's nature's way. If your husband is worried about it, he can spend more time with his son.

This doesn't mean he should spend time with him while he is smoking marijuana. Assuming that the few puffs would be puffed by your husband and not the baby, the sidestream smoke that drifts off the end of the cigarette -- even one made of plain tobacco -- isn't filtered by either a cardboard tip or the cigarette itself. This makes it particularly harmful, according to an NIH spokesman.

And would marijuana smoke affect a baby's brain? No one knows.

NIH, however, does have very good evidence that teen-agers and preteens who smoke a lot of marijuana don't perform as well as they used to -- and their brains are more developed than your baby's.

You also have to be much more careful about drinking.

Alcohol settles everywhere in the body except the fat and the bones. When you drink wine, much of the alcohol is diluted in your six quarts of blood and carried through your milk supply in this same proportion. This may not seem like much, but it's enough to go to a baby's brain and drug his central nervous system.

Furthermore, his liver doesn't produce enough of the right enzymes to metabolize the alcohol, so it is going to stay in his system longer. The hydrocortisone in his body can be affected too, which is why a nursing baby may get a balloon face and a paunchy stomach for 2-3 days if his mother has had too much to drink.

As for guidelines, nursing mothers would be wise to avoid the foods that produce gas, like cabbage or onions, for this can give a baby colic. Other mothers discover that their child might cry or be sickly in some way if they drink milk or eat a lot of dairy products; or that their baby is sensitive to the wheat they eat, or the chocolate, or that the caffeine in the coffee keeps the baby awake. If your baby cries when he isn't hungry, he needs you to watch your diet at least as much as his.

As for your weight, neither nursing nor a Caesarian section should have caused a big gain. The operation probably encouraged you to take it easier and nursing does too. Now you have to exercise and diet as well.

If you don't lose soon, this new weight is going to seem more normal every day until you suddenly realize that leg lumps make jeans look like jodhpurs! A black day.