How can you rectify the sleep disorder problem for the children?

Children's sleep. Some sleep issues with children may be passing phases, but anything that persists over time or interferes with the child's functioning or their health should be assessed by a Pediatrician or Psychologist sleep expert.
Sleep specialist. A sleep study may be required to get data on the sleep disorder and a sleep specialist referral will help with dealing with the disorder. Ask your pediatrician for a referral.