What are the similarities and differences between Isabel Burnell and Lil Kelvey?

Isabel is the older sister of Lottie and Kezia, Isabel is entitled and finds validation in having money. She is bossy and wants to be the first to brag about the doll’s house to the other girls at school. Lil Kelvey is perhaps a character foil for Isabel. Lil Kelvey is unassuming and poor. She is mocked by other kids and feels self-conscious about her poverty.