|“||I was merely anxious about you, Tommy. Surely you are not vexed.||”|
Barbara was among those who doted on her youngest brother Thomas when he was young and sickly, frustrating the boy. Even when Thomas recovered past his sickly days, it was a while before the family outgrew the habit.
In 1901, Barbara, Eugenia, and their mother, Sophie, followed Thomas to Devil Tavern, the chosen haunt of his friends. If it had not been for Sophie's understanding and respect of the young boys' private time, the sisters would have followed him to their rented club room. Matthew Fairchild saw them and was appalled.
In August 1903, the day after the Carstairs family arrived in London, the Institute held a ball to welcome her and her family to the city. Barbara attended alongside Oliver Hayward, a suitor with whom she had an understanding. They were seen holding hands and dancing until Barbara suddenly fainted — a dark tendril appeared from the ground, grabbed her by her ankle, and attempted to pull her down into the shadows. When she came to, Cordelia and Anna had cut her dress and corset to help her breathe. She claimed she just had a dizzy spell as she had simply forgotten to eat.
Despite her sibling's worry over the past night, Barbara wished Thomas to leave her alone on the beach with Oliver in hopes that he may propose.
They were soon attacked by demons—even though it was daylight. Due to her perfect Sight, she saw glimpses of James's shadow realm and saw the demons in the park, similar to the dark shapes she had seen the previous night, before the others, and was the only one who saw that it had been a demon that attacked Piers Wentworth. During the ensuing melee, Barbara was bitten and poisoned by one of the demons and collapsed.
She was brought back to the Institute infirmary and treated by Silent Brothers. Her brother stayed by her side, holding her hand while Brother Zachariah tended to her. The Brothers soon opted to put her and the other two poisoned Shadowhunters to sleep, in hopes it would slow the poison from spreading until they could find a cure.
Barbara passed away after only a few days. In her final moments, she was delirious and lashed out, clawing at Oliver who had been crying by her bedside. This unknowingly spread the infection to Oliver who fell ill and died shortly after.
Barbara's death had a devastating impact on her friends and family. Her sister broke down and collapsed upon hearing the news. Her mother and father traveled to Idris to be with Eugenia and comfort her. Gabriel and Cecily took Thomas in during this time.
Thomas and the others dedicated themselves to not only making a cure but finding and putting an end to the demon attacks in her name.
Growing up, Barbara was very affectionate and protective over Thomas—to the point where he found it smothering—and was often considered more gentle than her sister. She was somewhat of a romantic and wanted to become a dutiful wife rather than a strong Shadowhunter.
- Nothing but Shadows (alluded to)
- Cast Long Shadows (mentioned only)
- Every Exquisite Thing (first appearance)
- Chain of Gold
- Chain of Iron (mentioned only)
- She was presumably named after Gideon's mother, Barbara Pangborn.
- An error in a "found" family tree states that Barbara died in 1917, whereas she in fact died in 1903.
- A scene in the Clockwork Princess epilogue, set in 1937, mentioned "Gideon and Sophie's two girls" and was previously believed to have been referring to Barbara and Eugenia; unless their parents have another daughter or this scene is later retconned, this may be a continuity error.
- Found family tree, a Clockwork Princess extra
- An Illustrated History of Notable Shadowhunters & Denizens of Downworld
- Cast Long Shadows
- Chain of Gold
- "They want the things society says they're supposed to want...in Barbara and Eugenia’s cases, to marry well within Shadowhunter society and to be ladies rather than warriors." Cassandra Clare on Tumblr
- Clockwork Princess