Orla'ath was Miss Quill's sister. The two always fought in the nest and, at one point, Orla'ath even tried to kill her sister. The last time Quill saw her she threatened to rip her heart out with her bare hands. She died at the hands of the Shadow Kin when they invaded Rhodia.
A branch of the Lankin used her image, presented in human form, to try and feed off of Miss Quill's grief. Charlie stabbed her in the hand with a screwdriver and she was absorbed back into the great trunk. (TV: Nightvisiting)