"Only poor,
That when she dies with beauty dies her store."
The plain meaning of this is, that beauty was 'her store,' she had nothing but it, poor praise indeed from a lover! I would read, with Theobald,
"That when she dies with her dies beauty store."
The meaning would then be that, as the whole store of beauty lay, as it were, in her, by not marrying and transmitting it to her children, she would cause it to die with her, and would thus be poor as leaving nothing after her. The same idea is expressed in the poet's first and following sonnets: in Venus and Adonis we have—
"For he being dead, with him is beauty slain,"
and other passages of a similar nature. See also Twelfth Night, i. 5.
"'Tis the way