Note to Romeo and Juliet, 5.3.207: "That warns my old age to a sepulcher"

Romeo and Juliet,
Act 5, Scene 3, line 207.
That warns my old age to a sepulcher: i.e., that tells me that I, the older one, belong in a sepulcher. As a parent, Lady Capulet must feel that she ought to die before her child does, and that her child's death makes her want to die. However, Juliet's mother isn't very old; earlier in the play she said to Juliet, "I was your mother much upon these years / That you are now a maid," so she's less than thirty years old.