It were extremely short lives, the longest lasted 2 years after her turning back to being 16. One only lasted to the ball she is attending now (chapter5+).
So she was just an extremely traumatized abused child trying to do everything to get her family's recognition.
Only after talking to her father and brother right before her 10th death, she realized, they will never love her or at least acknowledge her existence.
yes, the 10th time she came back she decided to live freely and take revenge. the 9 lives she had lived was with hope that her family would love her if she would be obedient, weak, and loyal to them.. her ultimate goal and point back on those 9 lives was to be loved by her own family, and when she kept on getting betrayed until the end. she decided that enough is enough, and she would live how she deserves to live.
If I'm not mistaken.. she said she live 9 times already right?.. so what's the point of live for 9 times??