Like everyone else I do think it's about a woman trapped in an "American dream/suburban" life with an abusive husband she inevitably murders. "17 years and all that he gave was a daughter" -- her moon. A crystal, or cold heart, lucid and departed life left behind -- she has no emotion for what she has done to her husband and finally feels free of a life that was slowly killing her.
Like everyone else I do think it's about a woman trapped in an "American dream/suburban" life with an abusive husband she inevitably murders. "17 years and all that he gave was a daughter" -- her moon. A crystal, or cold heart, lucid and departed life left behind -- she has no emotion for what she has done to her husband and finally feels free of a life that was slowly killing her.