According to the original plans, Tess had a family. Wife and son before arriving in Boston. But these two were infected. She killed her husband, but she couldn’t do the same to her son. So he locked him in a basement and theoretically he still lives, as a Clicker.
There were two ideas. One for the basement door to close and loud noises to be heard, the other for Tess to share her story with Joel and Ellie. But both Mazin and Druckmann imagined that this backstory would create a confrontation between Tess and Joel.
“(Tess) is brave enough to dare to hope,” the co-creators said, noting that’s something Joel currently refuses to do.