"but thesegirls aren't cheap labour - they're people" Act 1
Sheila recognises the inequality --> 1st hint that she might have socialist views and is open-minded. She also isn't afraid to disagree with her capitalist father
"girls" - humanises Eva and tells Birling to look at the working class as human beings not as 'working robots'
"It was my own fault" - Act 1
She's remorseful and accepts responsibility, but only blames herself ('my' - possessive pronoun)
Her reaction juxtaposes to her parents' who accept no blame
"It's you two who are being childish - trying not to face the facts" Act 3
believes that it doesn’t matter whether the Inspector is a real police officer or not. She is only concerned that they all harmed someone --> depicts responsibility and maturity
"If she'd been some miserable plain little creature, I don't suppose I'd have done it" Act 1
She was envious of Eva's looks and felt entitled to be better than her
She used her power to fire Eva even though she did no harm --> problem with class system
"She was a very pretty girl too... I couldn't be sorry for her" Act 1
"pretty" - adjective, she's insecure of her own looks and envious of Eva's beauty, so she used her power to 'punish' her --> shows the power upper class had over the working class
"You don't seem to have learnt anything" Act 3
"You" - direct address--> accusatory towards her parents
declarative sentence - upper classes in Edwardian society were reluctant and too stubborn to change --> depicts Sheila's disgusts toward her parents
"I know I'm to blame - and I'm desperately sorry" Act 2?
"I", "I'm" - Personal pronouns --> she only blames herself
"desperately" - shows character development --> Sheila represents the younger generation, Priestley uses her to give hope and show that the younger generation can make a change to society.