Perhaps you don’t realize that some religions believe in reincarnation.
According to the work done by Dr. Michael Newton (fascinating book The Journey of the Soul) with clients in very deep hypnosis, the oversoul sends out only a portion of its energy to incarnate. It is possible to have several people in many places coming from the same source. A child would be free of the mental structures we acquire as we grow and there are many examples of people with partial or total recall. This has nothing to do with religion but the wonderful world of spirit.
what religion does this 4 year old observe?