Here, in the third line of the poem, the speaker first describes the turtle as female. Closely tied to this initial identification of the turtle's gender is an explicit acknowledgement of the turtle's at-risk status. Life is full of risks, for men as well as women. But in many parts of the world, women have been especially vulnerable to abuse and exploitation.
[…] almost any slope Defeats her modest hopes. (6-7)
Think of the uphill battle American suffragettes faced in seeking the right for women to vote; think of the many setbacks and defeats they had to overcome. In isolation, the words "slope" and "defeats" have no specific connection to women's rights. But consider the context. With its connotations of "shy," "meek," and "unassertive," the word "modest" has strong connections to the "lady-like" notions associated with traditional women's roles.
She skirts the ditch which would convert Her shell into a serving dish (10-11)
Once you become sensitized to the connotations of individual words in the poem, the word "skirts" may jump out at you. Here, "skirts" clearly means "avoids," but it also can refer to a woman's garment (for more on this, check out our "Detailed Summary"). The term "serving dish" also connotes the domestic realm traditionally overseen by women. Plus, notice how the turtle protects herself: through avoidance rather than confrontation. (Unlike the Teenage Mutant Ninja Turtles, this traditional gal has not cultivated her martial arts skills.) In these ways, the poem again subtly links women with ideas of repression and violence.
[…] never imagining some lottery Will change her load of pottery to wings. (12-13)
If, throughout your life, people in authority keep telling you that you're unworthy, it's hard not to believe it yourself. In line 13, the word "pottery" recalls the earlier reference to "serving dish," connoting even more humble dinnerware. This female turtle doesn't even dare imagine that she has the capacity to rise above the limiting circumstances of her life.
Her only levity is patience, The sport of truly chastened things. (14-15)
"Chastened" can mean "subdued," "repressed," or "punished." These meanings are certainly relevant to bias against women. And one synonym for "patience" is "endurance." Throughout history, women have suffered physical, emotional, and economic subjugation. Their ability not only to endure, but also, over time, to progress in their struggle for fundamental human rights is cause for celebration, don't you think? Maybe the little glimmer of "levity" and "sport" in the poem acknowledges this hope for a brighter future.