What are the similarities and differences between Sheila and Mr Birling?

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 her mother's callousness. When they get the news of Eva's suicide, Sheila is upset. As much for having Gerald's affair officially unveiled as anything else..... but she stays calm. Something unexpected.

Sybil Birling is callous. She is unsympathetic, snobby, and quite nasty. Sybil is cold-hearted, very conservative, and self righteous. Where everyone else in the novel seems to feel some responsibility for Eva's death, Mrs. Birling feels nothing. She calles Eva "impertinent" and feels that her financial status absolves her of everything.