What is the effect of envisioning “aged years” as needing a staff in these lines from the passage?

by that time will my aged years
perhaps a staff require:
a.
it evokes the comfort that the elderly feel knowing that a younger generation will replace them.
b.
it reminds the reader that the speaker will be aged by the time she can see the youths as adults.
c.
it suggests that the speaker feels distant and isolated from the young people of her time.
d.
it reveals how weary the speaker is of waiting to see what effect she might have had on others.

to her sister mistress a. b.
by isabella whitney (excerpt)

and grant if that my luck it be
to linger here so long
till they be men, that i may see
for learning them so strong
that they may march amongst the best
of them which learning have possest.

by that time will my aged years
perhaps a staff require:
and quakingly as still in fears
my limbs draw to the fire:
yet joy i shall them so to see,
if any joy in age there be.