Why does the author title the section "Born Bad" In the story The House On Mango Street?

Esperanza notes the fact her mother said she'd been born on an evil day with her inconsiderate and what most would consider cruel treatment of her dying aunt. The girls were merely playing a game in which they imitated the actions and movements of others..... usually a movie star.... someone they only knew through magazines or film. None-the-less, on this day, the girls chose a sick woman to make fun of..... and her aunt, that's the day she died, leaving the girls with the guilt and shame born through their actions.