Jo grew up as Josephine Forrest in Los Angeles. She is the daughter of trancer hunter Jack Deth and Lena is her mother. Jack first met Jo in Trancers III when he revisited Lena in 2005 to get information about the trancers, but he didn't know that the kid was his own child. She was played by Samantha Jordan, but was credited in the film as Cathryn instead of Josephine.

He had to save Jo's life in Trancers 6 by inhabiting her body in 2022 on an important mission. Unlike Jack, Josephine's diet consists mainly of health foods like tofu and carrot juice, and she's a bit of a space nerd.

In Trancers 6, Jo was portrayed by Zetti Sullivan, in what proved to be the last film, not counting the sequence from Pulse Pounders that was fully restored in 2013.

Jo has a half-sibling in Orpheus.