Hello! Thank you for trusting HCM! Acid reflux disease can flare up at night, especially after first laying down, as the acids and undigested food can begin to travel back into the esophagus. Some of the most common include gastroenteritis or stomach flu, migraine headaches, parasites, appendicitis, motion sickness, hepatitis, food positioning, pancreatitis, ulcer, severe heartburn, head injury, cancer or ketoacidosis. Please consult your pediatrician. He will examine her and treat accordingly. I think I answered your question. If you have more questions, feel free to ask. Take care