A Storm of Swords
On the suggestion of Varys, Tyrion Lannister hires her as Sansa's new maid together with Shae, replacing earlier maids that spied on Sansa for his sister Cersei. Tyrion considers her a good choice, as her earlier service for Renly Baratheon has given her some practice at being blind, deaf and mute. However, Shae complains about her loud snoring, which Tyrion also notices.
After the death of King Joffrey and the disappearance of Sansa Stark, she is questioned by Lord Tywin Lannister, telling him of Sansa's constant praying, both in the sept and at night in the godswood.
A Feast for Crows
Brienne of Tarth searches her as part of her investigation into the disappearance of Sansa Stark, finding her in a brothel in King's Landing, where she does the washing. Brella explains that she has no knowledge of Sansa's disappearance. She complains bitterly that now that she has served two traitors to the crown, she can no longer find work with nobles and thus has to do washing for whores. She tells Brienne about Sansa's constant praying, both in the sept and at night in the godswood, and suggests that Sansa most likely fled north, as that is where her gods are. She also informs Brienne about how Sansa begged King Joffrey for the life of Ser Dontos Hollard, which makes Brienne believe that Ser Dontos helped Sansa flee and that finding him will lead her to Sansa. Brella also shares that there was little warmth between Sansa and Tyrion Lannister, making Brienne believe that Sansa might have fled her husband just as much as King Joffrey's murder.