I believe I do have a timeline of events that you might find illuminating.
Her parents are hesitant, but are somewhat reassured when Gally tells them that Susanna has recently married a Captain Noone and that he will be travelling with them.
Gally’s brother, Newt, has been on the sidelines of the discussion. When their parents withdraw to discuss the matter, Newt asks Gally more questions about Susanna’s supposed husband.
Newt deduces that Captain Noone is a ruse. He tells Gally that the play on words with ‘no-one’ is not as subtle as she might think it is.
Gally tells him that it is too late to change the name from Noone, not least because she and Susanna are planning to rename their act ‘Midnight & Noone’.
The two discuss Gally’s new stage name of Midnight, agreeing that it is better suited than Nightingale given Gally’s low voice. This gives Newt an idea for a song in which Gally would play the part of a man who impersonates birds.