She is a fanatic woman who never agreed with her mother, Melinda’s approval to donate her organs, even for his brother Sam Watts whom she disgusted out of his negative behaviors like being a drunkard so he can redeem himself to be a better person. Her hatred towards her brother was so much that she stated that humanity is as pathetic as Sam and thus, decided to usher a new era once became the Grandmother of Universal Brotherhood. Once she gained the Grandmother Rank, she hired Dr. Holmes, who was originally a former Chop Shop Surgical Assistant named Silas Fornsberg who faked his own death to kill those who receive her mother's organs so when her mother buried, her body would be whole again, with the formerly transplanted organs placed back into her own body. When Melinda eventually was buried alongside Sam Watts, the protagonist confronted her and asked her about her true intentions, in which she responds by expressing her wrath on those whom receive her organs for an unknown reason. Mother Lynne Terestrian, the elf who goes with her, tries to calm her down to no avail. She later flees, but not before send her hired mercenary to dispatch the protagonist and his/her friends.
Jessica confronted protagonists again, whom shocked that her potential sacrifice for her ritual, Marie-Louise, freed by them. Here, it’s revealed that Jessica has turned 2 of her own follower into monsters named True Form Workers. She then proceed by revealing that her disgust with her mother’s generous decision to donor her organs includes toward Sam Watts, and also Sam’s negative traits has encouraged her for her evil plans to usher a new era. She demonstrates this by revealing that the monsters’ immortality nature where whenever they died, their spirits would remain lives and reconstructed their damaged husks. Thanks for both Marie-Louise and Baron Samedi’s help, they escaped.
It’s later revealed when the protagonist captured by the police after stealing an Aegis, substance that can potentially kill bugs, Jessica has made enemies where one of protagonists’ ally, Aljernon the elf, and James Telestrian III, whom revealed to be half sister of Jessica and father of Mary-Louise. From the meeting that held by protagonist, revealed that Jessica’s monsters were spiritual beings that once invaded earth centuries ago that lived in astral and physical realm, and has ability to possessed weak-willed person and turned their body into the physical version of their spiritual forms. Currently, she also attempt to summon the Queen of the beast as well. That’s why Telestrian at this moment working on Project Aegis that creates a weapon in form of fluorescing astral bacteria that can kill the insects’ astral manifestation.
By the time protagonists, with help of his new friends (namely Harlequin) managed to enter the heart of the hive, she has prepared to summon the Queen bug Spirit that would possessed Lynne. They managed to subdue both Jessica and all the presening bugs, leaving Lynne in presumably catatonic state. Ultimately, as result of the failure in the ritual, the Queen Bug now abandonded her and left her for mercy. From here, protagonists can either gave her the justice or ended up let her die. In either way, however, she feels remorse, as most of her negative actions mostly fueled by the bugs.
She is revealed to be a fanatic member whom only cared on her family’s purity which made her manipulated by bugs.