Priestley establishes Mrs. Birling as bossy and controlling at the start of the play in order to set up the inevitable conflict with Inspector Goole when he arrives in Act Two
Mrs. Birling complains that Inspector Goole's comments are a trifle impertinent and in Act Three she describes his questioning as peculiar and offensive
Priestley uses Mrs. Birling's discomfort to having a police inspector refused to obey her as an example of the wealthy middle and upper-class's complacency when it comes to the law
Mr. and Mrs. Birling clearly see themselves as above the law and they struggle when faced with someone who is moral and insisting that justice is served
Priestley presents Mrs. Birling as an example of how petty and self-centered or egocentric some people can be when they themselves live easy and comfortable lives whilst others are struggling to eat
Priestley uses the charity committee, who were swayed by Mrs. Birling's prejudice, to demonstrate how fallible this system was in 1912 when there was no NHS, no benefit system and no access to contraception
Mrs. Birling's low opinion of the working class and her involvement in the charity committee suggests her ulterior motive is more about how it looks to wield power rather than a desire to help people
The Birley family's use of domestic staff, like Edna, highlights the old ways of doing things where working-class women were made to work in difficult conditions for very little money
The notion of being privileged runs through the play, with characters who are apparently unaware of their privilege taking advantage of others who are less privileged than themselves
Priestley questions the morality of Edwardian society through his depiction of a privileged family and their attitudes towards others who are less fortunate than themselves