Though initially cold and distant towards Henry, she managed to bond with her upon discovering she was nearly raped by Clay Boone and that she has the unique ability to teleport.
Jenna's mother passed away sometime during her youth.
Sometime prior to the series, her father became engaged with his girlfriend Cleo Coles, single mother of Henry Coles, and both moved in with them. Jenna was not at all happy it.
After breakfast one morning, Jenna complains to her father about constantly having to drive Henry to school with her. Thomas responded by saying she was family, to which Jenna coldly countered that she wasn't, which was overheard by Henry. Thomas told her have a heart and to help him out.
On the drive to school, Henry tells Jenna that she and her mother will be "out of her hair soon", as according to her, she and Cleo never stay in the same place for more than six months. Jenna responds by saying that her [Henry's] mom is already beating her dad's [Thomas] record, agreeing with Henry that it's only a matter of time.
The next day, Jenna is driving Henry to school with her again, while bragging about how awesome her car is, presumably taunting Henry about her recently sold car. Henry responds by asking why she's so happy as she is now stuck as her "chauffeur" for the rest of the year.
At school, Jenna is conversing with her two friends at their lockers about one of them (Patty) has gotten a new tattoo. Henry, over at her locker, listens in on their conversation. Upon noticing Henry watching them, she turns to her and asks if she's got any concerns. Henry merely turns away. Patty then asks Jenna if she was coming with them on Saturday, to which she answers no. Another of their friends, Brenda comes up and tells them about a rumor about Clay Boone (Patty's ex) hooked up with fellow student Tracy Stafford.
At home that afternoon, Jenna is chatting with Patty over FaceTime in her room about her new dress. Henry comes into Jenna's room unannounced, for which an annoyed Jenna tells her to knock. Henry tells her she needs help. She shows Jenna recently damaged bedroom, and tells her that she was with Clay in his truck, much to her intrigue, until she learns that he attempted to rape her. Continuing on, she reveals that while all that happened, she suddenly ended up back in her bedroom, along with the door to Clay's truck.
Driving back to the scene of the incident, both girls investigate the damaged truck and discovers that Clay is still alive. Henry then calls 911 and reports a car accident, but flees the area with Jenna, whom agrees to Henry's request about not informing their parents about the incident.
The next morning, news of Clay's accident has spread throughout the town and Cleo and Thomas inform the already-aware teens of the situation. The two then go to school with Henry suggesting they forget about last night. Upon entering the school, they both notice everyone's mourning for Clay and Jenna is suddenly embraced by grieving Patty.
Leaving school, Henry is confronted by Clay's brother Lucas Boone, who has discovered Henry was with Clay during the accident. Trying to feign denial of any knowledge of what happened, a scared Henry frantically tells Jenna to drive them home, but is quickly followed and cut off the road by Luke. Jenna reluctantly leaves her behind so she can deal with Luke. She then speeds away to get help.
Upon arriving home, Jenna seeks out her father to inform him of the situation, but is shocked and somewhat spooked that Henry is already there. Completely bewildered, she stammeringly asks how she got back, but Henry answers she is unsure. All she can tell is that she was in his trunk, and she suffered a seizure and blacked out. Jenna then attempts to call the police, but Henry dissuades her as they have no way of explaining what's happened. Seeing Henry's mom arrive (to take Henry to the doctor's), Jenna suggests she tell her, but she refuses.
Jenna is working on her laptop that night when Henry comes in, having been dropped off by Thomas. Henry asks if she's eaten anything, to which Jenna agrees, having made herself soup. Henry then jokes about who makes themselves soup, causing Jenna to joke back people like her. The two then converse about what the doctor said about Henry's condition, and reveals to Jenna that the doctor has her on some new meds that are gonna "fix everything". After learning Henry has not spoken to anyone about Clay, she suggests a hotline to call for help, but merely rebuffs her, saying she liked it better when they didn't talk.
When Henry arrives home after being gone for hours, a concerned Jenny confronts her. She makes it clear that she wants to be there for her, and agrees to do whatever she wants with her. Henry then gets her to smoke pipe, which she reveals is her first time smoking. This shocks Henry who knows Jenna occasionally drinks an apparently distasteful liquor, for which Jenna counters by mocking her graffiti. Both of them then share a laugh. Jenna then reveals that Henry's bedroom was formerly her mother's workshop and had tried to teach her to sew, which she thought was stupid and revealed that two minutes after she died, she threw up in her bed. Bringing up the subject of Clay, Henry tells her that she hopes he dies, somewhat shocking Jenna. She then encourages Henry not to let him get away with it.
Later at school, a concerned Jenna informs Henry that Clay has awoken from his coma. This causes Henry to suffer another seizure, and run into the girls' restroom. Jenna becomes shocked and horrified when their surroundings begin to crumble, causing her to flee in fear.
The school is then evacuated upon hearing the disturbance. Worried about Henry, she and Townes (whom she runs into) rush to the destroyed restroom and discover Henry is no longer there. She and Townes find her awhile later. Townes decides to look into Henry's situation a bit more and has her and Jenna come to his house in 34 minutes.
In the car, Henry decides to talk to Clay to see what he knows before the truth ever gets out, knowing how dangerous his family is. She then asks Jenna to talk her to Townes' house, believing he's the only one who knows what has wrong with her, and she needs to know before confronting Clay about it.
Arriving at his home, Jenna discusses with Henry about how Townes is good at science, and has some trouble distinguishing reality from fiction. This only causes Henry to remark that she knows a lot about him despite not liking him. His mother Meghan answers the door, surprised that Jenna has returned and addressing her by her full name: Jenna Faith Hope, much to Henry's amusement, who then jokes how her parents thought "Faith Hope" was good name.
Townes brings them to his room and Henry reveals how she suddenly ends up back in her bedroom whenever she feels the world is "pulling away from her." Jenna adds it also happens when she's scared. Townes theorizes Henry can teleport and decides to test her to to prove it. Jenna remains somewhat skeptical as it's believed scientist can only teleport elementary particles; copies of the original. She believes it would make more sense if Henry generated a wormhole, which draw objects to it, similar to what happened when the school restroom imploded.
To test her, Jenna and Townes have her jump off a high cliff into a lake. It fails initially, but Henry tries again later that night by herself. Unknown to her, Jenna had followed her. Seeing Henry apparently drowning, a horrified Jenna attempts to jump in after her, only to witness a sudden implosion in the water. Realizing Henry has teleported, an astounded Jenna calls her cellphone and Henry answers, confirming fear is indeed the trigger to her power.
A few nights later, Jenna (as member of the Science Club Decathlon) accepts the award for first place on Townes' (the team captain) behalf due to his absence.
Sometime later, Henry is hospitalized after suffering a massive seizure. Jenna converses with Cleo, and out of concern for both her and Henry reveals that Clay tried to rape her and how she is intimidated by Bill Boone, much to her shock and horror.
Arriving home, Jenna hears a noise upstairs and encounters a mysterious man, who chases her to the kitchen. Armed with a knife , she manages to keep him at bay, telling him to leave. He tells her he's searching for Henry,. She soon arrives, having teleported from the hospital. After disarming Jenna, Henry confronts him. He attempts to calm her, knowing of her ability to teleport. He suddenly stabbed in the back by Jenna. Both are stunned when he teleports away, confirming there are others like Henry out there. Jenna reveals she found him in her room. Henry then reveals that she's seen him years ago as a child with her father, and he had safeguarded her from him. Upon learning that Jenna told her mom about Clay, Henry races off to his Bill Boone's garage, knowing she'll confront him. Jenna then joins her.
Arriving on the scene, they find police are there and learn about the shootout that took place and how Cleo was taken by Luke. Guilt-ridden and scared, Henry tells Jenna that she was right, had she told her mother the truth, she wouldn't been at the garage, and that because of her lies, she got an innocent kid killed. Jenna considers calling Clay, as he is Luke's brother and might know where he is, to which Henry reluctantly agrees.
Jenna and Henry stop by the Boone house in search of Luke and find the house has been set on fire by the Millers. Henry runs in to see if Luke (or her mother) is there. Worried, Jenna then call Townes to have him go to her house should Henry teleport back to her bedroom.
Jenna arrives a while later and finds out Henry saved Clay from the fire. She also informs her that her mother is safe, and Thomas was bringing her home from the police station, meaning they should get rid of Clay. Jenna and Townes decide to take Clay to the hospital.
On route to the hospital, Clay confronts Jenna about if she knew what Henry did to him. He then criticizes her for not caring about what Henry did to him, only for her to harshly rebuke him by reminding him of how he assaulted her. Hearing this, an enraged Townes pulls over and attempts to hurt Clay for actions, only for Jenna to convince him that Clay is not worth it. They then continue on to the hospital.
The next day, upon arriving at school, Jenna asks Henry if she has marijuana, revealing she now has an interest in doing drugs, much to Henry's astonishment and amusement. She confirms she does, and gives Jenna a blunt. The two then have a discussion about Jenna's being someone she isn't such as acting like others to please them or just be herself. Henry then wholeheartedly encourages her to embrace who she is.
Later at lunch, Jenna decides to sit Henry and Townes instead of her usual friends, shocking Henry. Upon hearing Townes' suggestion about training Henry to control her powers, Jenna supports the idea and promises Henry that she and Townes will be there to help her no matter what. Henry complies.
She and Henry later go bowling that night with their parents.
Sometime later, Jenna visits Townes in his house and observe a YouTube video of a teleporter. Townes identifies him as Michael Pierce, who had disappeared from Bermuda two days into his vacation, and is now dead, with his body having washed up on the coast of Newfoundland. Jenna tells him it wasn't the same teleporter who was in her house, who had taken Henry's dad years ago. Townes also reveals Pierce was a geneticist working for Clear Tech which makes solar panels and electric cars. Just then, Townes' computer is hacked and is left a message: "If I can find you, they can too."