The poem begins with the speaker describing an anonymous woman, saying that in order "To feed one" child, "she worked from home." There, she "took in washing, ironing, [and] sewing" to make ends meet. With only a single "small mouth [to feed]," the speaker says that the woman's "life was a dream."
The poem suggests that because the woman's "Work" is manageable and leaves her time to actually enjoy her life, she doesn't mind doing it. Her life feels balanced. The fact that she's able to "work from home" while caring for a young child also suggests the way that her work fits into her life rather than the other way around.
The poem's nine quatrains (or four-line stanzas) each correspond not only with a segment of this woman's life and work but also with an era of human history. The poem can thus be read as being about a single woman feeding her children while simultaneously working as an extended metaphor for the relationship between human beings and the planet.
In this metaphor, the woman can be thought of as representing "Mother Earth," while her children represent humanity. The opening stanza suggests the beginning of human history, when people lived in small communities, taking only what they needed from the earth. Back then, the poem implies, the earth was happy to provide for her "children."
Notice the use of asyndeton in line 2:
took in washing, ironing, sewing.
The lack of any coordinating conjunctions between "ironing" and "sewing" indicates that the list isn't meant to be complete. That is, these three tasks—"washing, ironing, sewing"—suggest the sort of work the woman generally does to provide for her child. There are other tasks along these lines that she also performs, but the speaker doesn't need to list them all out separately—this short list implies them.
The poem is written in free verse, allowing it to feel natural and conversational. And while it does not follow a set meter or rhyme scheme, it contains plenty of musicality, such as the burst of /oo/ assonance, /s/ alliteration, and /p/ consonance in line 3:
One small mouth, a soup-filled spoon,
The sounds in this line are harmonious, working together to evoke the simplicity of the woman's life caring for only one child. These smooth sounds also suggest the balanced and proportional relationship between earth and her "children" in the early days of humanity.