Stories…When an idea becomes a story

Sometimes stories float around in a writer’s mind a long time before they come to any real form.  I have a character that keeps coming to mind as I am trying to fall asleep. She is a strong woman with three lives.  She passes in and out of each of the three lives every year on August first.  She actually ages and is reborn into a new life and three personalities every 80 years or so. She refers to herself as a “Reborn.”  Remembering each life that she lives is one of her demons. She is  reborn so many times that eventually she begins running into the family members and acquaintances over and over.  She begins to understand that she is not the only reborn and develops a theory of who in her lives has the same condition. If she admits her condition to another, will they put her in a mental hospital or will she find another reborn? Each lifetime she lives, she lives one less year in the next life. Eventually, she will run out of lives and then what? What if you had to relive going through adolescence, break-ups, paper-cuts, childbirth, weddings, funerals, and the roller coaster of living over, and over, and over.  What would you question about life, about God, about existence?  Let me know if this sounds like a decent story to develop or pursue. Should I continue to roll it around in my mind or put pen to paper?