Since the narrator in "The Leap" is telling a story about someone else, her characteristics are implied indirectly and inferred or deduced (1) from how she speaks of the Anna Avalon, which adds to the tone of the story, and (2) from what she says about herself. Firstly, the narrator tells how Anna chose between her great love for her husband, as he was being propelled through the air to certain death, and her love of her unborn child (the baby didn't survive the tragedy after all). The narrator also tells how Anna, in order to fight of the depression that followed her injuries, the loss of her husband and the loss of her baby, learned to read and write with the help of the doctor attending to her dramatic injuries.
The narrator also indirectly reveals that even tragedy couldn't close down Anna's heart because she fell in love with her doctor and they married, which resulted in the existence of the narrator. Therefore from the tone, it can indirectly deduced that the narrator is a grateful, appreciative and loving woman herself, who is not unmindful of the greatness in her mother's life. As a result the tone is one of admiration for a life that was lived with genuine selflessness and heroic moments.
More can be deduced about the narrator through what she says about herself. Firstly, she says that she owes her life to her mother. This implies a correct sense of obligation and reinforces the sense of gratitude deduced from what she tells about Anna and the tone. Further, she says that she has given up her "failed" life to come and read to Anna following her father's death and her mother's cataract caused blindness. This reveals much about the narrator. It reveals that even though her mother had a successful, accomplished, confident and happy life, the narrator was unable to learnfrom her mother how to attain these qualities in the same way that she learned how to high-dive from her mother. It further reveals that along with a sense of obligation, she also had a right sense of duty and reciprocity toward her mother. She also says that she will "read all night" if she must. The fervent spirit with which this is uttered tells that the obligation and duty that the narrator feels comes from a deep and profound feeling of love and gratitude and respect born of her mother's selfless love and heroism.