Mrs. Mallard can be honest with herself because she is alone.
In this section of the story, the setting plays a crucial role in providing Mrs. Mallard with the solitude she needs to explore her true feelings about her marriage and her newfound sense of freedom. Being alone allows her to reflect deeply and embrace emotions that she might have suppressed while in her marriage. This isolation allows her to experience a range of emotions, from grief to exhilaration, as she contemplates her future without her husband.