Is reincarnation immediate? My brother died four years ago, and my two-year-old exhibits many of his characteristics and always points him out in pictures even though I haven’t explained who he is or brought attention to him.
In the Autobiography of a Yogi Paramhansa Yogananda writes of his promise to a young disciple, Kashi, that if he died young Yogananda would find him again when he reincarnated and help him once again onto the spiritual path. The chapter “Kashi, Reborn and Rediscovered” has many fascinating insights into reincarnation, but it also answers your specific question: Yogananda “found” Kashi six months later in the womb of his new mother. Visiting the family sometime later, Yogananada noted how similar the infant looked to the Kashi he knew before. Yogananda fulfilled his promise and guided Kashi to a Himalayan master.
According to what I have read, not everyone reincarnates so quickly. Our karma determines when we will find a compatible family. As I understand it, if you had a strong bond with your brother, it is quite possible he would be drawn to a life with you and your wife.
Puru (Joseph) Selbie