Maggie and Don had been having marital problems caused by the latter's affair with his business partner, Wendy Goodson, which Maggie's friend, Sue, told her about. Once she found out, Maggie unleashed her vengeful rage towards Wendy, casting a spell on her that caused a hair-dressing machine that Wendy was using to overheat and kill her. Wendy wasn't Maggie's only target, as the revenge-driven villainess also targeted Don's co-worker, Dewey Stevens, as she accused Dewey of covering up Don's affair. She used her powers to power up a drill to kill Dewey inside a porta-potty.
After Sam and Dean Winchester informed Don Stark about the deaths, believing that he could be next, the brothers went to the Stark home and found photos of the victims at the home, covered in Maggie's blood. Dean saw a photo of Don's assistant Jenny Klein and took it just as Maggie returned home, but shortly afterwards, the evil Maggie took out another photo and unleashed her hex towards Jenny, doing so believing that Don was having an affair with her (Jenny later confirmed that she wasn't). Meanwhile, Maggie's hex worked its evil magic on Jenny at her home, as tiny hearts appeared in the cupcakes she was eating. Just as she was about to become Maggie's latest victim, Sam and Dean arrive and save Jenny, doing so when the former destroys Maggie's hex coin.
Maggie is later confronted by Don, who warned her to stop what she was doing, only for Maggie to respond by destroying Don's bust. During Maggie's charity art auction, the paintings are sabotaged and Sue ended up beheaded by a tray, and it was there that Don was revealed as a warlock and the culprit behind the actions. Sam and Dean, having now learned that both Starks are witches, headed to their house in an attempt to kill them with a spell, which didn't go well because the ingredients weren't quite right. The couple then planned on eliminating the Winchesters, leading to Sam and Dean trying to coerce the couple into talking things out. During this, it was revealed that they were (at least) eight centuries old and that both of them were adulterous, with Don revealing that Maggie had an affair with Christopher Columbus before his voyage in 1492.
While talking it out, the couple used their powers on Sam and Dean, including Don sending a horde of bees to swarm over Dean, which Maggie gleefully approved. The couple later regained their love for each other, with each one saying that they couldn't kill the other. Despite Sam and Dean saving their marriage, Maggie still made an attempt towards them, as Don pulled out a hex coin left by her after subduing a Leviathan who was after them.
- Charisma Carpenter also played Lifetime film villainesses Laura Clifford and Callie Chalmers in 2006's Flirting with Danger and 2011's Deadly Sibling Rivalry, respectively.
- Charisma Carpenter appeared as henchwoman Triana in the 2009 episode "Marked" for the TV series Legend of the Seeker.
- Charisma Carpenter also played recurring villainess Kendall Casablancas on Veronica Mars, and later appeared on Lucifer as the evil Jamie Lee Adrienne.