The Question and Answer section for An Inspector Calls is a great resource to ask questions, find answers, and discuss the novel.
I believe that would be Crofts Limited.
Sheila is an air-head, she's flighty, she's materialistic, and immature, but she has a pretty good heart. She calls her mother "mummy" but refers to her as "mother." This signifies the differences between she and Sybil, as Sheila disapproves of...
This quote refers to Mr, Birling's outlook on life. He believes that you put yourself at family first, at the expense of all others.