Very young children very rarely are afraid of the dark. They don`t yet have a concept of "monsters hiding in the dark". The fear develops as a child grows. A new fear should not be viewed as regression. It should be only viewed as a new concept that has formed in her mind.
Don`t dismiss your child`s fears as unimportant. It is a very real complication in her life. Listen when she talks. Your ability to listen often helps her understand her fears better. Talking about it and having you answer her questions will play a major part in getting over the fear.
Don`t put her down because of her fears. It may mean nothing to you as an adult. But that is a real trauma that she is facing. Laughing at her will only make things worse. Not only will she still have her fears, but her opinion of herself will take a beating too. She will now have to confront her fears and her self worth too.
Leave a little night-light on for her. She can manage her fears better if a little light can show her that there are no creatures hiding in the dark.
Check on her a few times at night. If you think she is getting restless, sit by her and pat her back to sleep. Knowing you are visiting her a few times at night will put her at ease.
Eating spicy foods at dinnertime can also cause nightmares. Feed your child an hour earlier and avoid any kind of spices. Keep the food as bland, yet tasty.
Ensure your child visits the toilet before it goes to bed. Going to bed on a full bladder can also upset a child.
Encourage your child to pray or meditate before it goes to bed. This helps calm the mind and soothe the child. Or tell him a story about how God will watch over little children at night and protect them from any harm.