Jessica Hamby (Deborah Ann Woll) is a newborn vampire unwillingly created by Bill Compton (Stephen Moyer). She was a beautiful young woman growing up in a strict, religious family when Bill created her. He made her as penance for his murder of a fellow vampire in defense of Sookie Stackhouse (Anna Paquin). Initially, Jessica loves the freedom and power that comes with being a vampire, but ultimately her restlessness begins to tax Bill's patience.
In the second season of the show, she begins a romantic relationship with Hoyt Fortenberry (Jim Parrack). Their relationship seems doomed from the start. He is a kind young man while she is an energetic and hungry vampire. More specifically, complications arise because her hymen keeps growing back every time she and Hoyt have sex (since she was a virgin when Bill turned her). Ultimately, the disapproving opinion of Hoyt's mother causes further disruption in her and Hoyt's relationship. Jessica responds by feeding on a trucker and accidentally killing him which results in her being blackmailed by the mysterious vampire mercenary Franklin Mott (James Frain) and eventually completely fractures her relationship with Hoyt. Things only get worse when Hoyt begins dating another woman in a poorly conceived attempt to make Jessica jealous.
Bill's tempestuous relationship with Sookie coupled with Jessica's estrangement from Hoyt has caused her to become lonely in Bill's lonely mansion. She eventually decides to enter human society by becoming a hostess at Merlotte's.
Her ambivalent attitude about being a vampire is perfectly expressed in the following quotes: "Just because my fangs popped out doesn't mean I am going to use them on you." and, "No more rules... I'm a vampire!"