Based on the passage, two instances of situational irony are:
1. "Come over here and listen to a story," said the aunt, when the bachelor had looked twice at her and once at the communication cord."
This is ironic because the aunt calls the children over to listen to a story, but the story ends up being boring and uninteresting.
2. "In a low, confidential voice, interrupted at frequent intervals by loud, petulant questionings from her listeners, she began an unenterprising and deplorably uninteresting story about a little girl who was good."
This is ironic because the aunt begins telling the story in a low, confidential voice, which implies it will be an exciting secret, but the story is actually boring and uninteresting, eliciting loud complaints from the listeners.