"David, let Granny have that," said Miriam Croumer, 61, her voice colored with affection as she retrieved a bunch of keys that the 19-month-old had heaved over the side of his crib.

The two have become close friends since Croumer started visiting David, his mother and his brother and sister twice a week.

Croumer is the family's surrogate grandmother. Her visits mean that Clarice Smith, David's mother, can take a break from caring for her son, who needs constant attention because he was born with a blockage in his windpipe. He still breathes with the help of a tube placed in his throat that resembles a plug in his neck.

While Croumer holds David, plays with the energetic youngster or watches him sleep, his mother can take a nap, do the laundry or chat with friends on the telephone.

About 50 Washington families with chronically ill children who need constant supervision now look forward to a couple of hours of rest and relaxation each week because of Croumer and the other volunteers with the Family Friends project.

Established by the National Council on the Aging Inc., nearly a year ago, the friends project matches its 40 volunteers, who are at least 55, with low- and moderate-income families with children ranging from infancy to 12 years old.

The volunteers, who include three males and a husband and wife team, visit their assigned family for about three to four hours usually once a week to provide companionship and to help alleviate the isolation and stress faced by many parents of severely ill or handicapped children.

During a volunteer's visit, a parent must stay at home but can take a nap, catch up on household duties, or spend time with other children.

The families pay nothing for the volunteers' help. The projects runs on a $250,000 budget, raised largely from private foundations, said Meridith Miller, director of the Family Friends project. The project pays the volunteers $12 to $16 per visit depending on transportation costs.

"I feel as if David is my grandson," Croumer said, while holding the infant in his Southeast home. "I hope he'll be able to spend the night with me in the future," she added.

Croumer, who retired three years ago as a supervisor for the U.S. Government Patent Office, continued, "The project gives me something worthwhile to do. It makes me forget about my aches and pains because I know David needs me."

Clarice Smith also looks forward to the visits. "I'd be lost without the project," she said. "I can concentrate on my GED General Education Diploma studies and spend more time with my other two kids," Rudolph, 11, and Sabrina, 6.

She added, "I now have someone who listens and understands what I'm going through." She also learns from Croumer, she said. "For instance, Miriam has no problem combing David's hair. But me -- I first have to chase and catch him!" she laughed.

David, who has undergone two operations to improve his breathing, sleeps attached to an air compressor system to prevent him from choking. An oxygen tank is nearby for emergencies.

His crib is next to his mother's bed. "I don't sleep soundly," she said.

The Family Friends project resembles the Foster Grandparent Program, except that foster grandparents visit children who live in institutions.

"The project is aimed at strengthening the entire family," said Miller. "And because our volunteers go into homes having no medical support staff, they are trained more extensively than foster grandparent volunteers."

However, the friends' volunteers cannot give physical therapy or medicine to the youngsters they visit.

Tamar Palmer, 63, cares for Rosalind Bishop, 12, who suffers from cerebral palsy and is mentally retarded. Palmer, a nurse who became a recluse after her husband died in 1981, said she joined the project at the urging of a close friend.

"The program lifted me out of a deep depression, and helped me reestablish contact with people," Palmer said. "Participation in the Family Friends Project has given my life new meaning."