What is the explanation for this?

My 4 year old niece said this to my aunt, "Did I come from somewhere else to get to you, do we get reborn after we die into a new body?" My aunt is very strict about media and she doesn't know where she could have picked that up from. She also talks about "being other people" before she was in this life and "surviving in a compound where she was d" which she was taken to for "doing nothing." How can a four year old articulate something like that, I just don't understand?