What is significant about the connection Lily makes between May and Our Lady?

Lily sees salvation for May's pain through Mary. The "Lady in Chains" provides a sense of respite for Lily when she thinks about May. May becomes a symbol of suffering and resurrection: a Christ-figure of sorts through the mercy of Mary. Below is an explanation of the daughters of Mary by GradeSaver.

The Daughters of Mary, as a group of black women in the South in the 1960s, have clearly been exposed to their share of discrimination. The Boatwright sisters have attended college, but they have not really been able to find appropriate jobs outside of the black community, except for domestic positions within white households. The women feel the societal chains that bind them to a specific status position. The story of Our Lady provides women with hope for advancing their lives regardless of the "chains" that hold them down. Rather, they realize their ability to harness their internal power to enhance their lives.