What is the main conflict in The Grave by Katherine Anne Porter?

The Grave" appears as part of a group of stories within The Leaning Tower called "The Old Order." Taken as a whole, the stories present the family history of a young girl named Miranda: each very short tale depicts a scene from their past in a nostalgic, poetic tone that is nonetheless tinged with a vague sense of darkness. The last story of the group, "The Grave" begins with Miranda, nine years old, playing with her brother Paul in the empty graves that formerly contained many of the relatives from the earlier stories.