No, it is not recommended to give melatonin to a 3-year-old child. It is important to establish a good sleep routine for your child, which may involve activities such as avoiding screens before bedtime, keeping the bedroom only for sleeping, and ensuring there are no stimulating objects in the room. Encouraging outdoor play during the day can also help regulate your child's sleep cycle. It is best to consult with a healthcare professional for guidance on improving your child's sleep habits.