What is the significance of the "wailing wall" ?

August and Lily discuss May’s wall. May built the wall out of stones from the river. She has spent ten years building it. August explains that May is very susceptible to feeling the pain of others. She treats the pain as her own. Lily wondered what it would be like if someone shared the pain she had. August tells Lily that May had a twin sister April, and May would suffer the symptoms of April’s injuries and sickness. When April died as a young child, May began to absorb the pain of the world. April had suffered from terrible depression as a child, and at age fifteen she killed herself. June and August had decided to start the wailing wall to assist May with her pain. May writes down the names of people in pain or events that caused pain, and she puts the notes in the wall.