Final answer:
The question asked about Danny's nicknames for Molly and Mary Kate cannot be answered as it stands, because the reference provided is related to Henry James' novella 'Daisy Miller', and there is no mention of the characters Molly and Mary Kate in the given text.
Step-by-step explanation:
The query about Danny's nicknames for Molly and Mary Kate appears to be a question related to a specific literary work or text. However, based on the given reference, "Her name is Daisy Miller!" cried the child. "But that isn't her real name; that isn't her name on her cards.", the characters Molly and Mary Kate are not mentioned. This excerpt is from Henry James' novella Daisy Miller, and it refers to the title character, Daisy Miller, who is also known by her real name, Annie P. Miller. Unfortunately, without additional context or information about the literary source mentioning Danny, Molly, and Mary Kate, providing their nicknames is not possible. If the reference pertains to a different text or character interactions, additional details would be necessary to accurately provide an answer.