[…] She pulled,stooped to pull harder— (2-3)
We don't really see it until the end of the poem, but Persephone is trying to escape her mother's overprotection. Or at least, that's one way to read it. In this quote we see her desperation to be older, bigger and more in control of her life, or at the very least, her flower picking. Really, she's hoping she can pull the future into the present.
It is finished. […] (7)
As much as Persephone wants to make things speed up and experience new things, it ultimately leads to an end to time altogether. The allusion here hints at death, when humans step out of time's flow.
Remember: […] (9)
Yeah, it's only one word, but it perfectly captures the mother's mindset. All she can do is try to keep her daughter in her memory. If she can just keep her innocent, if she can just make her follow the rules, maybe time will stop and she won't grow old.