Are there any reliable natural remedies for children who have attention problems?

Yes. There are several causes of this symptom. Allergies, neurotransmitter disruption, nutritional problems and toxins (heavy metals, chemicals) are the most common. Treatment depends on which of these are contributing to the symptoms. It's best to see a doctor trained in these approaches. To start with, eliminate the junk/refined food, exercise, and have a regular sleep schedule.