Since losing her mother, Lily has been trying to fill a hole deep within her. She longs desperately for a sense of belonging that she certainly cannot find with T. Ray. More specifically, she longs for the love of a mother.
When she finds August and her sisters, Lily finds the mothers she has been searching for, but she doesn't realize it at first. Instead, she still lives in the past, in a place of hurt and loss—holding tight to the love she feels abandoned her as a young child: "There had never been any voice in the wind. No mother out there singing. No bottomless love."
In chapter 13, Lily breaks. In breaking, she finds her bottomless love in the black Mary. She releases all of the pain that she's been holding onto so tightly for years:
I felt a powerful sadness, not because of what I'd done, as bad as that was, but because everything seemed emptied out—the feelings I'd had for her, the things I'd believed . . . I lay in the emptiness, in the tiredness, with everything—even the hating—drained out.
After doing this, Lily allows herself to be filled back up with hope. She looks at the black Mary and imagines crawling inside a little hole just above her abdomen. Symbolically, this represents claiming another mother figure, one capable of the bottomless love she's always longed for. Later in that same chapter, Lily rubs honey into the Mary, bonding with the sisters she's come to love.
In the final paragraphs, Lily calls this Mary a "muscle of love," acknowledging that in her, and in this new family she's created, she finds the sense of acceptance her soul has longed for. She closes the novel with this realization:
And there they were. All these mothers. I have more mothers than any eight girls off the street. They are the moons shining over me.