A Flower will not trouble her — Word's Burden

A Flower will not trouble her, it has so small a Foot, 1
And yet if you compare the Lasts,
Hers is the smallest Boot-
(F.1648/J.1621)
[1] Flower:: figure of speech; ornament of words. her:: ED herself. small:: insignificant. Foot:: a combination of syllables consisting a metrical element of a verse.
[2] Lasts:: loadings, burdens (over the wording).
[3] Boot:: profit, gain; the benefit of a word's meaning. ED considered herself burdered the word less.