Both Rowan and Sabine are disciples of the Lady of the Light. The Lady goes my many names. Sabine knew her as Aurora.
At one point, Rowan learns that Bezos has captured the Lady, or her avatar in the Shadowfell and is drawing power from the lady for an apocalyptic purpose. Rowan and Sabine marshaled the forces of the Heroes of the Drowned Quarter to liberate her.
She is served by her herald Nigel Ramsbottom.