The trouble with her heart might be that she doesn't have one
"She thought herself again in comparison with her mother at thirty-four and she pinched her arm and smiled. Seeing that her mother or father neither had been much to look at, she had done very well" (O'Connor 68).
I pretty much had to stop right here because this woman is just bashing her poor mother and father. I am one of seven kids and my parents did absolutly everything to support my family, love us, and experience life with us. So it really bothers me that she has yet to look at what her parents have done for her and her siblings. Parents sacrifice their lives so that their kids can have lives. A paragraph before this quote she mentions that she thought she might have heart problems but refused to go to the doctor. Personally, I feel she didn't have much of a heart because she was always focused on herself.