Being ashamed of her life. In the book Esperanza gets lots of stares and passive agressive comments from her peers, teachers and strangers about her living conditions. Her family tells her that she was born on the "devils day" and it greatly effects the way she sees herself and her Aunts health. She greatly wants to leave her family and never come back when shes older. She doesn't like the life she has and wants to put it behind her.
[sorry if some details are off I haven't read the book in almost a year]