A Post article on March 24 about the District's new commitment to adoption was accompanied by a photo of a family smiling with love at handicapped six-year-old Cathy, adopted last December. For Cathy's social workers, what was most heartwarming was not that she had become toilet-trained or had begun to speak. That progress occurred over time. For the first time, in this photograph with the Gross family, we saw her smile.

There aren't many families like the Grosses, who "don't think wild horses could get Cathy away from us." But there are many children like Cathy. Small social-service agencies are best able to take the risks necessary to serve children like Cathy, but we are finding it difficult.

The city government recently has begun to support a program to plan for a permanent family for each child--to keep children home with their own families, to return them home to strengthened families or to find adoptive homes for them. Half of the 2,000-plus children who remain as wards are teen-agers. Many have been in the child-welfare system a long time. Abuse and neglect and many moves to and from homes or institutions have left these adolescents--and even the younger children in the system--angry and mistrustful. Many are mentally retarded or have physical handicaps. Almost all are black, from environments of poverty and despair.

Peirce-Warwick is one of the private agencies serving these children. After more than 100 years as a traditional infant-placement agency, Peirce-Warwick in 1976 changed its mission and now serves only older black children and handicapped children who are public wards. Its goal is to work with the city government's new program to find adoptive families.

Special children need special families. Most middle-class families are not comfortable with children who will not achieve. Often, to place these children we choose families who would be rejected by traditional agencies. Examples: a family in which the father has spent time in prison for bank robbery; families whose members are reformed alcoholics or have serious health problems. These families, having battled with adversity and settled for less, can love children who have had similar experiences, and they won't give up easily.

Not all of these adoptions succeed. Realistically, we have to be willing to take risks, to choose the lesser of evils. A 14-year- old who has to return to an institution because his single mother can't control him and because she has to work two jobs is still better off with a committed and lov- ing family that visits him. A "better" adoptive family is probably not available for him. Even our successful placements may not seem so. Behavior that looks vastly improved to a child's social worker may still seem entirely unacceptable to the child's new school teacher. Most of the children we place don't do well in school. We have to define success realistically. We see Cathy Gross smile for the very first time. A family may have done a magnificent job of helping a child if that child spends only a few months in jail as a young adult and then goes straight.

The agencies serving special-needs children also need public understanding of this risk-taking. The new administrators in the city's department of human services acknowledge the value of public-private cooperation. But all public officials have to deal with their own doubts about entrusting children to risk-taking programs that they do not control. They are, after all, answerable to their supervisors, who must answer to elected officials, who are very conscious of public opinion and the media.

Administrators of both private programs and public agencies constantly fear that something will go wrong that cannot be successfully explained. If a child were picked up for shoplifting, could you explain his adoption by a family in which the father has a prison record? How do you explain the adoption of an 11- year-old multiple-handicapped girl who develops medical problems after she leaves a "safe" institution to live with a family whose resources are already stretched?

We may know that the girl has learned to dress herself and get about independently only because she lives with a family. Usually the gains are intangible, and the children's problems are too complex for explanation in a short news item.

Sometimes the children appear unhappy, angry or mentally ill. But without these risky programs, many more of them would be institutionalized for life, at incalculable cost both to the children and to the taxpayers.

This is why many private-agency administrators were concerned when The Wilderness School for Boys, a program of For Love of Children, recently closed--temporarily, we hope--after some publicized problems. This school served troubled boys 10 to 16, with the goal of returning them to their families or to substitute families. Last year, for example, the Wilderness School accepted from St. Elizabeths a 14-year-old District ward who is now back in school and reunited with his parents.

In a school in the West Virginia woods, the boys, with staff guidance and support, took responsibility for helping each other. They tackled academic skills, self-understanding and self-control as they planned and carried out daily activities of cooking, cleaning, building and playing.

In February, a new boy joined the camp. He and several other boys ran away. The new boy's cousin drove them to a local newspaper office, where the boys told the editor that they had been victims of abuse at the camp. The charges were widely publicized, although West Virginia authorities later determined they had no basis in fact. Through a combination of events, however, the school's license lapsed and the other boys were sent home.

FLOC has assessed what is needed to re- establish the school and has appealed to District officials to work with it in building a stronger program. Of the 500 boys between 10 and 16 in the D.C. foster-care system, many could benefit greatly from this program. Rather than pulling back support in the face of controversy, public and private agencies should work together. The city's human services department did this in setting up its new system of contracting for adoption services--which is how Cathy found her home.