Before the Sudden DepartureEdit
In stark contrast to her somber personality later in the show's chronology, Jill was a happy, young teenager.
After the Sudden DepartureEdit
Season 1 Edit
After the events of October 14 series Jill is disillusioned. Though no members of her own family depart on the 14th, Jill struggles to cope in the post-departure world as she witnesses what structure she once had in her life dissipate. With her mother, Laurie, becomes a member of the Guilty Remnant, and half brother Tommy disappears, Jill's only support is her father, Kevin Garvey and her best friend Aimee. Jill appears initially reckless, willing to act out pointlessly.
She looks for her mother in the GM and tries to get her to talk to her. When her mother doesn't speak she decides to join and her mother lets her. Even when they set the houses on fire. She eventually is rescued by her father.
Season 2 Edit
In season 2 she, her father, Nora, and Lily move to Jarden. Jarden is a little town in the middle of a parc called Miracle in Texas. Nobody departed from there, and it's a safehaven for a lot of people, that's also for Nora who wanted to make the move to there. Jill is really good with Lily and looks after her a lot and takes care when Mary stays there for a while.
Jill starts a relationship with her neighbours son, Michael. Michael is very religious and that is something Jill finds sometimes difficult to deal with.
Season 3 Edit
Jill is at college and lives at college. She doesn't want to stay in Jarden because if she stays with her father it would make her mother sad. But if she would stay with her mother Laurie would stay up all night apologizing.
Jill is one of the few characters explicitly said to have witnessed a departure. In the novel it is her best friend Jen with whom she is on the couch watching youtube, in the show it is an unidentified student at the science fair who ends the circuit excitement Jill and Tommy participate in.
In the novel Jill's hair is suggested to be very short as a result of her rebelliously shaving her head, whereas throughout the show her hair is long.