Final answer:
The question about Gerda summoning a doctor for her father's heart attack cannot be answered with the provided texts, as they involve different characters and scenarios from Henrik Ibsen's play 'A Doll's House' and other unrelated stories without a character named Gerda.
Step-by-step explanation:
The student's question, 'Why is Gerda not able to summon a doctor the night her father has a heart attack?' implies a situation that is not explicitly detailed in the provided text excerpts. The extracts given are from Henrik Ibsen's play 'A Doll's House' and other unrelated texts.
In the case of 'A Doll's House', the character Nora is preoccupied with her own issues and is not depicted as dealing with her father's heart attack.
Therefore, without additional context, it is not possible to answer why Gerda is unable to summon a doctor, as there is no character named Gerda or mention of a father's heart attack in the context given. This appears to be a confusion with characters or plot points not present in the provided text.