Death comes quickly when Death wishes to come quickly. But at this moment, with Tracey's deepest desire to be released from her pain, her overwhelming fear and utter despair, Death ponders.
After all, there is the child to consider.
That small vessel of lifeforce: it has a right to protection, surely? And no one will protect it better than the mother, correct?
And there's the child's father. It would lose its spirit if Tracey were not to continue existing.
Death. Or the Shade of Death, if you will, leaves the apartment as quietly and unnoticed as it entered.