Carol Bowman in her book Children's Past Lives: How Past Life Memories Affect Your Child, describes how to be helpful to your child when he or she talks about a past life memory. These are her words:
Stay calm: Breathe. Clear your mind so you can devote your full attention to your child.
Acknowledge: With assuring words and a loving tone of voice, acknowledge your child and the truth of the memory. This keeps the memory flowing and ensures a positive outcome.
Discern: Listen closely to discern the facts and emotions of the emerging story. Also, look for the underlying themes of the memory, and how they relate to your child's present life.
Allow emotion: Always allow your child to follow the memory wherever it leads, and to express all emotions, no matter how disturbing or intense.
Clarify past and present: With loving assurance, clarify for your child the difference between images from past lives and present reality.
After the intital shock of actually listening to a past life memory, the last point may actually be the most surprising to parents - that young children sometimes believe that their memories happened in THIS life. If this happens, you may have to simply explain that what they remember is from another life and that they are now safe in their new body with their current family.