hysterical - historic use of the word is important, negative connotations for women
sheila uses it = internalised misogyny Gerald infantilises Sheila: “she’s had a long, exciting and tiring day” “she’s obviously had about as much as she can stand”.
Sheila is more emotional and remorseful. She takes the blame.
“mustn’t try to build a wall between us and that girl” - symbolic of socialism. socialism breaks down the walls in society that capitalism builds, it stops division in a society. (this is what Priestley is trying to say).