Final answer:
Sheila sees the injustice in the treatment of the lower classes in 'An Inspector Calls' through her recognition and criticism of the upper class's blindness to corruption, her belief that lower class workers should be treated with kindness, and her understanding of the importance of generosity towards those in need.
Step-by-step explanation:
Quotation 1: "Let me tell you this, You with your precious eyes, you're blind to the corruption of your life, to the house you live in, those you live with". This quote indicates that Sheila sees the injustice in the treatment of the lower classes by highlighting the obliviousness of the upper classes to the suffering of others.
Quotation 2: "I tell you, there's something wrong that no talk of 'Liberte' or 'Egalite' will do away. If I had the making of men, these men who do the lowest part of the world's work should be machines, nothing more, hands. It would be kindness. God help them! What are taste, reason, to creatures who must live such lives as that?" This quote shows Sheila's recognition of the unfair treatment faced by the lower class workers.
Quotation 3: "If any moral element enters in these scenes, it seems to lie in a requirement of generosity on the part of those who have something to give to those who have nothing." This quote suggests that Sheila acknowledges the need for compassion and generosity towards the lower classes.