Rowena was initially antagonistic towards the Winchesters as she saw Crowley's relationship with them as diminishing his power. The Winchesters often called on her help with magic, and Rowena assisted when she saw a benefit for herself. Over time, she became an ally in their battles, albeit motivated by the benefit she saw for herself in helping them. Rowena had a particular bond with Sam -- they were both tortured by [[Lucifer]] and saw his true face, and share the struggle of living with that experience.
In 2018, Rowena began killing people and their [[reapers]] to get [[Death]]'s attention, as she blamed herself for Crowley's death and the path that her abandonment led him down in life. During this, the reaper [[Jessica]] reveals that in the book [[Death]] keeps on her, it is written that she will die by Sam Winchester's hand. While [[Billie]] refused to bring Crowley back, the experience ended with Rowena deciding that working for the greater good will
be her redemption. She subsequently aided the Winchesters in their efforts to return to [[Apocalypse World]] and on occasions when they needed her expertise on a situation or case.
In 2019, after the release of the [[Hell Ghosts]] upon the world, Rowena chose to sacrifice herself to save the world by using her own body to imprison all of the souls and demons and cast them back into Hell. At Rowena's request, and with great reluctance, Sam was indeed the one who fatally stabbed Rowena. Following Rowena's death, Sam inherited [[Rowena's Spellbooks|her magical stash]], which she intended since Sam was described by Dean as "Rowena's protégé."