"It is difficult," says a New York Civil Liberties Union lawyer, "to get the courts to recognize that children have their own rights."

The NYCLU has been fighting a complicated two-year custody battle on behalf of four young sisters on Long Island. The girls want to stay with their foster parents, George and Dorothy Lhotan of Hicksville, N.Y., instead of returning to their natural mother. But after two appeals, in April the N.Y. supreme court finally ordered them to leave the Lhotan home. The two younger girls, Cynthia, 9, and Catherine, 10, were sent back to the mother, Patricia Wallace, in Long Beach, N.Y. The two older sisters, Patricia, 12, and Cheryl, 13, were placed in an interim foster home while a federal court studied the case.

"Before, nobody cared about us," said Cheryl. "But it was so different with the Lhotans. Somebody cared. We had a father. I didn't have to stay up at night worrying."

Patricia Wallace, 33, who also has two young sons, was never married to the father of her six children. In 1970 she placed all of them in foster homes, saying she was unable to take care of them. "I was alone," declared Wallace recently. "My back was against the wall." According to the girls, they were neglected and often went hungry. (In 1972, however, Wallace was allowed to take back her two boys.)

All four girls say they want to live with "Mom and Dad Lhotan." George and Dorothy have three sons, ages 18 to 31, and would like to adopt the Wallace children. "I'm not even allowed to see them," says Mrs. Lhotan. "This is just awful. I feel they are old enough to have their own rights."

Soon after Patricia and Cheryl were placed in their new foster home, they ran away. "We wanted people to know we were serious," Cheryl told reporters. After hiding for a week, the sisters surrendered to police. A hearing is scheduled this week to decide whether the children's constitutional rights are being violated.

The ordeal has taken its toll. Cheryl, once an honor student, is failing in school. "I hate seeing myself go down the drain after I worked so hard," she says. Patricia's grades are also deteriorating. Both are worried about the younger sisters. "Cathy mopes around all day," said Cheryl after a recent visit with her. "She says everything has caved in on her."