The Forgetting Time by Sharon Guskin

This novel is not just about reincarnation, though strictly speaking it is, but is a fascinating treatment of what happens to us after we die, and what happens before we are born.

Single Mom Janie is trying to figure out what's wrong with her son Noah.  He's terrified of water (so getting him to bathe is a battle).  He has nightmares so vivid and scary that even she is frightened.  He talks about things that someone his age does not normally know.  And he asks to go home to his other Mother.  When his preschool orders him to get a psychiatric evaluation, his Mom is at her wit's end.  One of the evaluating psychiatrists thinks he may be schizophrenic and need medicating.  But when she meets Jerome Anderson, who has spent his life looking for an explanation concerning children who remembered past lives, they find themselves caught up in another explanation entirely.  

This book explores the lengths we will go to for our children, the regret that we have at the end of our lives, the hope we have in the beginning...and everything in between.  Interspersed with actual cases from the practice of real life psychiatrists, it makes for a captivating and thought provoking read.