|The title of this article is conjecture based on information revealed in the A Song of Ice and Fire novels and may be subject to change.
Barbrey Dustin, née Ryswell, is an unseen character mentioned in the second season.
When Tywin Lannister calls out Arya Stark on her refined speech for sounding too highborn rather than baseborn, she lies saying that her mother was a handmaid to Lady Dustin. As a result of working for a Lady, the fictitious mother taught her daughter to speak well.
In the books
In the A Song of Ice and Firenovels Barbrey Ryswell is the head of House Dustin and the widow of Lord Willam Dustin, who fought alongside Ned Stark during Robert's Rebellion. Lord Roose Bolton was married to her late eldest sister, Bethany.
Eddard Stark's older brother Brandon took Barbrey's virginity and she hoped to marry him, but his father Lord Rickard Stark was advised by his maester that it would be more beneficial to forge an alliance with House Tully, Lords Paramount of the Riverlands, by betrothing Brandon to Catelyn Tully. Barbrey has hated maesters ever since. Brandon and his father died at the outbreak of Robert's Rebellion, but the planned alliance between the Starks and Tullys continued with the marriage of Catelyn Tully to Brandon's younger brother Eddard. Barbrey's husband Lord William Dustin died at the end of Robert's Rebellion, fighting with Eddard Stark against King Aerys' surviving Kingsguard. Barbrey never forgave Eddard for William's death, and particularly because he wasn't able to bring William's bones back North to bury in his ancestral home. Combined with her anger at the late Lord Rickard because he forbid Brandon to marry her, Barbrey became very bitter towards the Starks over the years.
It isn't clear if William left an heir, because Lady Barbrey continues to rule House Dustin in his name. She usually leads House Dustin to act in concert with House Ryswell, which is still ruled by her own father Rodrik Ryswell. While her older sister Bethany died, her marriage made the Ryswells in-laws to Roose Bolton. Combined with Barbrey's ambivalence towards the Starks, the result is that the Dustin-Ryswells are the first Northern families to declare their support for the rule of House Bolton after the Red Wedding, and practically the only ones who do not passively oppose Bolton rule. Roose's relationship with the Ryswells may partially explain why the Dustin-Ryswells are the only families from the North who do not lose immediate family members in Roose's betrayals at the Battle of Duskendale and the Red Wedding, though this may simply have been because they had no family members present. Even so, while Barbrey is ambivalent enough to the Starks to provide lukewarm support to the Boltons (which is more than any other Northern house), she still lost many loyal soldiers in service to her House at the Red Wedding, and openly loathes Bolton's new allies House Frey.
- Barbrey Dustin at A Wiki of Ice and Fire (MAJOR spoilers from the books)