Final answer:
The question relates to English literature, discussing the literary device of using the sound of footsteps to create imagery and build suspense in narratives. Footsteps can indicate an important character's presence, a moment of anticipation, or a scene transition, contributing to atmosphere and character development in the story.
Step-by-step explanation:
The question "Is that her dainty footstep on the stair?" suggests a focus on literary analysis, specifically on the use of imagery and suspense in narrative texts. In the given passages, the sound of footsteps is a recurrent element that helps to build atmosphere and advance the plot.
These literary snippets describe characters reacting to the sound of steps, which could signify the arrival of someone important, a moment of anticipation, or a transition in the scene. For example, Lassiter's soft, silver-clinking step conveys his character's distinctive presence and the comforting effect it has on Jane Withersteen.
Furthermore, the reference to Mrs. Boldin's smile as she anticipates the delivery boy's reaction illustrates character development. Through the description of footsteps on the stair, these passages explore themes such as anticipation, worry, and the interplay of characters within a given setting.