In ”The Leap,“ what are the daughter’s fears?

The daughter in "The Leap" does not fear that blindness will impede her mother. She knows that her mother's memory of her trapeze act means that she is able to move around the house without even "brush[ing] a magazine onto the floor." Although she is blind, the mother seems to have been bolstered by the skills learned in her former life. In this story, the narrator recounts several near-death experiences both she and her mother have had: on every occasion, the trapeze artist's "catlike precision" kept her alive, allowing her to "live comfortably in extreme elements" and feel safe in the dark.
As such, the daughter really does not seem to have much fear, on her own part or on her mother's. Indeed, when she tells the story of how her mother rescued her from a burning house, she says she was not surprised to see her mother knocking on her bedroom window. She was only a little embarrassed for her mother to be seen undressed; briefly, she worried "what would happen if we missed the circle or bounced out of it." But instead of giving in to this fear, she "wrapped [her] hands around [her] mother's hands," and trusted in her mother's ability to save them both once again.