Hi Elisabeth....
The *very first* sign for me of "split" (as my twin soul put it) lives was back in the mid '80's. I had just begun to recall a certain life, and as we had *old* family pictures, I could see the similarities between myself and this other person. Our eyes are *the same.* Smile, gestures etc, but the undeniable evidence was the eyes. (For the first time, I saw that our eyes never change.) Another family member spoke of having been this person's wife, and when I looked at the old photo of the wife, I could see it was my relative, but there was a contradiction: the wife died 4 years after my relative was born. Nevertheless, their eyes were the same, and I accepted it, assuming I'd figure it out later on.....in the '90's, I identified a person who had been my niece, and this person had been born 2 years before my niece had died.
Since then I have identified more. Someone in another post mentioned quick reincarnations as being "rushed," but I don't necessarily see that. It as if they had gone thru careful consideration of their families, despite overlapping lives.
I am not certain whether the souls are really "split," or in fact "extended," that is, if the soul has not literally split up, but is in fact extended, or stretched, across the planes.
Btw the person who was my wife does not, I think, know she was 2 people for the first 4 years of her life. However she is aware of this reincarnation aspect, and at some point I should ask her how she "felt" during this period.
I hope this helps.