Charles Sheffield 
Ganymede Club [EPUB ebook] 

Lola Belman was a refugee. She and her younger brother were on one of the last ships to leave Earth as the bombs began to fall; by the time they left lunar orbit, they were orphans. Lola is now practicing as a therapist on Ganymede, and she has a new patient whose past is a mystery.During those years of chaos, many records were lost and histories forgotten, and it was an ideal time for anyone who wanted to conceal his or her identity. Now there is a small, dangerous group who will stop at nothing to keep Lola from exploring the past and discovering their existence.