To carry pure death in an earring, a casket, (19)
We here at Shmoop think this lady is really in love with death, fascinated by it. It's more than that, though. What she's talking about in this line is what she especially loves about poison. It lets her "carry pure death" around with her in secret, hidden in plain sight. The little ornaments that any lady in her time would have are suddenly turned into weapons. Instead of being a powerless female, she becomes a dealer of death. She's like a female Bond villain. She looks innocent, but then she pulls a knife out of her shoe. Okay, we'll leave our Bond obsession out of this…
And Pauline should have just thirty minutes to live! (22)
Again, our crazy friend seems to be really fascinated with poison. She loves how she can be sure of the person's death, and how she stays in control even when her victim has no idea what's happening. While they are feeling fine, she can count down to their death. We should mention also that Pauline seems to be just some random lady she knows. So her fascination with death is moving beyond the revenge plot and turning into general mayhem.
And her breast and her arms and her hands, should drop dead! (24)
Do you see how detailed her fantasies about death are? This is a lady who has really thought this all through. She doesn't just have some vague idea about poisoning someone. She imagines how it will spread out and destroy the victim's whole body. As usual, her revenge fantasy and her ideas about death seem to be all mixed up with her jealousy about other women, and her desire to wipe out the competition. That's the reason she never says anything about men dying.