She is the mother of Rick and Popuri, and works at the Poultry Farm with her children. Lillia is a calm and patient individual and is kind to everyone. She has an unknown illness which has no known cure, but is rarely upset about it. Lillia isn't outgoing, presumably, due to her sickness. However, she is shown to be very close to Sasha, and she often visits her. Lillia rarely leaves the Poultry Farm.
Lillia is shown to be close to her son and daughter. This is evident when Rick noted that he must take care of the family since she is sick. However, he would still disagree with her, especially when it involves Kai. Lillia supports Popuri's love for Kai.
Showing Lillia the Blue feather prompts her to say that her husband gave it to her when he proposed to her.