My daughter is not sleeping well for the last couple of days and wakes up at night? What could be the reason?

Could your daughter be stressed or anxious about something? Maybe at home or in school -- try to identify the stressors and reassure her. Sometimes, a change in environmemt, something that happened between friend can cause nighttime anxiety. Another reason could be something she ate close to bedtime maybe? My little brother gets nightmares whenever he eats too much before bedtime.