Jacinda grew up with her mother and sister Emily, all three of whom were powerful witches. Jacinda would often do sadistic things to torture Emily for the fun of it including turning her sister invisible for a week, trying to sell her soul to a demon, murdering Emily's rabbit and turning Emily's crush into a water balloon and popping him. Most of this was done before Jacinda "got mean."
Following the death of powerful witch Rowena MacLeod, Jacinda's family decided to raid Rowena's apartment for her magical stash. Posing as a neighbor checking on Rowena, Jacinda magically unlocked the door and began searching the apartment for Rowena's stash, quickly becoming frustrated when she couldn't find it. Jacinda began bleeding from the nose as she fell under a curse cast by Rowena upon her apartment to protect it. Attempting to escape, Jacinda collapsed and died within seconds, bleeding from nose, mouth and eyes.
Shortly thereafter, Sam Winchester arrived seeking Rowena's magical stash as well. However, Sam was unaffected by the curse as Rowena had specifically excluded him from it. Watching through a scrying mirror, Jacinda's mother and sister noticed this, as well as Sam's retrieval of a resurrection spell created by Rowena that could turn a spirit to flesh. The Witch Mother and Emily captured Sam and sought to force him to help them use the spell to resurrect Jacinda. Upon returning to the apartment with Emily, Sam noticed the girl staring at her sister's body and offered to cover it up for her. Emily informed Sam of the sadistic things Jacinda did to her, disturbing Sam, especially when Emily told him that most of her acts were before she "got mean."
After Dean arrived and entered a standoff with the witches, Jacinda's ghost appeared to help her mother and sister and flung Dean across the hallway with telekinesis. As Jacinda advanced on Dean, the ghost of Eileen Leahy appeared between them and flung Jacinda back into Rowena's apartment. The two ghosts struggled in the apartment, but Jacinda overpowered Eileen. As Jacinda strangled Eileen against the floor, Eileen pointed Dean to Jacinda's body. Dean poured alcohol from the bar over Jacinda's body and then set it on fire with his Zippo. Jacinda noticed at the last moment, but could only watch in horror before her ghost went up in flames.
From Emily's description, Jacinda was an extremely sadistic person who enjoyed tormenting her sister. Some of her actions include murdering Emily's bunny, turning Emily invisible for a week, trying to sell Emily's soul to a demon, turning Emily's tongue into a snake for yelling at her and turning Emily's first crush into a water balloon and popping him. Emily states that most of that was before Jacinda "got mean."
Powers and Abilities
Jacinda appeared to be a reasonably powerful witch.
- Spell Casting - As a witch, Jacinda could cast powerful spells.
- Reality Warping - Jacinda was able to turn her sister invisible for a week and transform Emily's tongue into a snake that left her with a permanent scar.
- Transfiguration - Jacinda was able to turn her sister's first crush into a water balloon which she then popped.
- Unlocking - With a one-word spell, Aperiatur, Jacinda succeeded in unlocking the door to Rowena's apartment.
- Invisibility - As a ghost, Jacinda was naturally invisible.
- Thermokinesis - Jacinda's presence caused the temperature to drop in the hallway her ghost appeared in.
- Electromagnetic Interference - Jacinda's presence caused lights to flicker.
- Telekinesis - Jacinda was able to throw Dean with telekinesis.
- Super Strength - Jacinda was able to overpower fellow ghost Eileen Leahy with ease in a physical fight.
- Powerful Magic - Jacinda died from a curse Rowena MacLeod placed on her apartment to protect it.
- Burning her body - Dean was able to destroy Jacinda's ghost by burning her body.
- Jacinda is the last character killed by Rowena on the show, dying after Rowena's death from a powerful curse Rowena had cast on her apartment.
- She was the second deceased witch in the show to become a ghost. The first was Maggie Briggs.
- It is unknown why Emily calls her sister for Jessie, as the Witch Mother reveals that her true name is Jacinda. Whether this was a deliberate choice or a script error is unclear.