Lithaen is Chaol's Westfall's ex lover who served as a maid to a lady of the glass castle three years before the arrival of Celaena
Lithaen had a romantic relationship with Chaol, but she cheated on him with Roland Havilliard for unspecified reasons. Chaol found her in bed with Roland, and as a result, his relationship with her ended. She then moved to Meah with Roland
Before knowing Celaena, Chaol had an affair with Lithaen. Chaol loved her, and he believed she loved him. Because of this, he was devastated after discovering that she had slept with Roland, Dorian's cousin
For reasons unknown, Roland discovered the relationship between Chaol and Lithaen and convinced her to go to bed with him. It is not known if she was in love with the lord, if she was blackmailed, or if she did it of her own free will. After her breakup with Chaol, she decided to move to Meah with Roland. It is not known what happened to her afterwards, but when Roland returns to Rifthold, he makes no mention of her.