In "The Leap," how does the narrator feel about the sister she never had?

In "The Leap," the narrator has conflicting feelings about her sister. On the one hand, the narrator feels no connection towards her: she refers to her as "the child," for example, and does not seem to share a familial bond with her: "She was a girl, but I rarely thought of her as a sister or even as a separate person really."

The narrator's sister was stillborn and never experienced life outside of the womb. The narrator, therefore, has no memories of her nor any other reminders of her existence, like photographs, except for her nearby grave. In the narrator's mind, she (the narrator) is her mother's only child. She explains that this may be the result of childish "egocentrism," an ability to disassociate herself from the rest of the world and the people in it.

That the narrator often visits the grave, however, suggests she may have some feelings towards her dead sister, or at least a sense of curiosity.