@mommy
It definitely feels like her mindset changed too much. From hating to the point of murder to developing empathy towards those she hated, there's a big gap.
To be fair, she spent some time imprisoned, doing sewing work and mulling over her mistakes. During that time, it appears that she wasn't consumed by her hatred. She faced the death penalty, then life imprisonment and then exhausted herself in prison. Perhaps she no longer had the energy to hate and this left her to consider that perhaps she should never have have followed that path in the first place.
It's not like it is all that positive though. She clearly does not wish to spend any time with her father's new family and has a defeatist attitude. Moreover, she is a noble lady and yet what she sees as a solution to her problem is to become a nun and avoid everything? That's pretty dark.