Q.Our 6-year-old is usually very sweet and adores his older half brother, but this boy lives far away, so my son is basically an only child. This makes it hard for him to adjust to our new situation.

We've started fostering young children and now have three with us -- a vigorous 16-month-old girl, a 4-year-old boy and a 6-year-old handicapped boy, but the boys will be with us for only a few weeks.

Although our son shares things fairly well with his friends, he refuses to share with these children and is getting very bossy and possessive. He has even asked us to stop fostering.

Also he sometimes cries about minor things, especially in the evenings, which he never did unless he was hurt. He says he's crying because he misses his big brother or our beloved family dog, who died last year. Or he yells that he wants us to leave him alone but is much better after a calm talk and some humor and hugs.

I have tried to include my son in activities with our foster children, and I encourage him to read to them and to assume some responsibility for them, but he barely participates unless he's doing something he really enjoys.

He and the 4-year-old do play with cars, chase each other and laugh quite a bit, but I'm worried that foster care is affecting him in a negative way and that he will have difficulty getting along with others in the future. What can we do?

A.It's wonderful that you have the time and love to foster young children, but don't expect your 6-year-old to participate just because it's something you enjoy.

And please don't take on the burden and the responsibility of caring for several young children at once. This isn't fair to your 6-year-old, to the foster children or to yourself. You may be licensed to fill four to five beds, but that doesn't mean that you have to fill all of them, or even one of them, all the time. Many new foster parents make this mistake and then find that they can't provide the harmony, comfort and peace that these scared, scarred children need.

You may be able to take care of several children at once when you have more experience, but for now just give your love and support to one foster child at a time. If you do that, your son probably won't be angry and resentful anymore.

There will still be times when you're asked to foster an extra child for a weekend or even a week, to give the parents a respite, but agree only if you know that the child won't stay longer. In foster care, "a few days" can turn into a few weeks and "a few weeks" into a few months. All it would take is an illness, a court delay or a mother who needs more time in drug rehab to turn your household into chaos.

You not only must say no to these requests, you also must ask your husband and your son before you say yes, for foster care affects the whole family. Describe the case to them, tell them what the child will need, and then ask them if they think you should take him in. They will probably say yes, but if they don't, or if either one agrees but looks unhappy, then turn down the case. Unless your family is united, your son will pay a price, your foster child will pay a price and your marriage may pay one, too.

If your son helps you decide which children to foster and when, however, he'll probably share his possessions better, as long as he doesn't have to share you too much. As busy as you are, he needs some time alone with you, and with his dad, every day, just as he had before you became foster parents. If he doesn't get it, he will blame the child -- and you -- for his loss, and he will be cross and stingy with his toys.

And when your foster child needs attention, don't ask your son to give it. Instead, do the reading yourself because this child is your responsibility, not his. Your son may do some of the entertaining when he feels more secure, but it should be his idea, not yours.

It's important to teach your boy to help others, but it's even more important for him to decide what kind of help to give, when to give it and who should get it.

Send your questions to Box 15310, Washington, D.C. 20003, or to advice@margueritekelly.com