Final answer:
The provided excerpts do not contain information regarding a character named Agatha, a glass coffin, or wishes related to discerning good from evil, thus an accurate answer cannot be provided based on the given text.
Step-by-step explanation:
The question refers to a character named Agatha making a wish while lying in a glass coffin, which is a scenario that doesn't match any of the provided excerpts.
The excerpts provided discuss various literary themes and characters, such as Lucy's distress during the Civil War, Editha's guilt in the face of a mother whose son was killed in war, Thecla's prayers for a woman's daughter, and introspective moments of personal anguish. However, none of these excerpts mention Agatha, a glass coffin, or the specific scenario in question. Therefore, it's not possible to generate an accurate response based on the given information.