Although none here can offer you concrete evidence, if you should decide to pursue the issue...I can give you a hint that always amazes even MY skeptical mind.
There are several books available that tell about very young children's frightening or near-death experiences. The stories are amazing...seeing angels, "nice ladies", relatives they've never known...and many make these claims to people other than their parents initially (so no "outside influence").
Just a thought for you...they, after all, haven't had a chance to be skeptical...yet!:>)