Definition of Irony
Throughout the story, Mother is extremely judgmental towards what she sees as her daughter’s burgeoning promiscuity. She says repeatedly that the girl is “bent on becoming” a “slut,” an outcome she clearly condemns. From Mother's comments about women known for promiscuity, the reader might expect her to warn her daughter off of sex altogether. However, in an instance of situational irony, Mother gives her daughter advice on how to induce abortion:
This is how to make a good medicine to throw away a child before it even becomes a child.
A central irony at play in “Girl” is the idea that femininity is considered natural and innate but also seems to require an elaborate training manual of sorts (which the story itself functions as). The fact that Mother has to specifically tell her daughter how to behave as a girl contradicts her apparent investment in gender essentialism, or the idea that there are innate biological traits associated with a person's birth sex. This implied belief is observable when she says:
Unlock with LitCharts A+Don’t squat down to play marbles—you are not a boy, you know.