I believe I do have a timeline of events that you might find educational.
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.
He and Susanna perform the original version of Woof, Woof, Woof, which tells the story of Albert Small.
Albert was a renowned bird impressionist as a child. However, when his voice breaks, he can no longer reach the notes needed to imitate birds like the nightingale. So that he can continue to perform, he changes to doing dog impressions instead.
Newt is reluctant to do so. In his life generally, Newt has no interest in the required activity and never intends to try it. He remarks that there are other ways of achieving the same effect.
At this point, Gally begins to speak more plainly. She had particularly hoped that Newt would do this for them, so that the kid would be the closest possible thing to being Gally’s own child.
This convinces Newt and they agree to the plan. He asks to be part of the child’s life in the role of an uncle.
Gally begins to explain the practicalities of the arrangement by asking if Newt knows Crewe.
Susanna thanks Newt for “filling in” and goes on to say: “I’m terribly sorry about breaking your duck.”
Despite not usually drinking, Newt takes a swig from a hip flask that Susanna has brought, since she points out to him that it is “rather a day for doing things you don’t do”.
They exchange awkward, but affectionate, conversation as they mentally prepare themselves for what they came to do.
She tells them that the act do not have tab music and that Miss Midnight (Gally’s stage name) would walk off stage if tab music was played.
They protest and ask to speak to Vanessa’s mother, but Susanna shouts from the wings that they are just to deal with Vanessa.
Gally sings the part of “the fellow on the cello”, while Susanna sings as “Susanna on piano” (pronounced “pian-ah”). The two characters are in love with each other, but both are under the impression that the other does not love them.
Vanessa is acting as stage manager for them.
Vanessa is speaking to members of her new sewing circle. They offer her their condolences on the death of her mother.
It transpires that there is some confusion in the group about the identity of Vanessa’s mother.
Vanessa tells them that her mother was Susanna Noone, who had died three years previous from a long illness.
Vanessa explains that Aunt Gally, as she calls her, was her mother’s companion. She tells them that, although Gally was like a second mother to her, they were not related.
The group are surprised to learn this, given Vanessa’s resemblance to Gally.
Uncle Newt is able to tell her that Susanna Noone was indeed her mother, despite Vanessa’s resemblance to Aunt Gally.
He does go on to say that Gally would have loved to have been Vanessa’s mother, and that, really, she was one of her two mothers in every meaningful sense.
When Vanessa asks what her father looked liked, Newt only says that he never met Major Noone.