She was once Metatron's friend but she stopped, after the fall of the angels. Sometime after, Rebecca decided to stay out of angelic conflict and opted instead to live humbly among humans. She won the sympathy of many other angels, who collectively were called the 'penitents'. Although vowing to reject violence and not being a threat to any of the warring factions, Rebecca and her allies were ultimately wiped out by Bartholomew's faction.
She was later buried, thinking she was her vessel, Darlene Foster. The remaining angel of her faction, Elijah, attended her funeral before he being confronted by Castiel.
Later, Castiel visited her grave, telling her he was sorry for causing all that chaos and for not being able to do anything for help. He also said although she had lost the war, she experienced a new way and that she had his respect for that.