Hexia felt little longing for the Divine Sword or the inheritance that Feng Jianxue had mentioned; such things were not must-haves for her. However, she very much wanted to fulfill the regrets her mother had experienced in the past.
Not only because she was her daughter, but also because she shared many of her mother's views on various matters. If some customs and rules were no longer appropriate, then it was time to sever them. People cannot always live in the illusions of the past.
Humans are strange creatures. If it is just for themselves, they can usually choose to endure and yield. But when it involves someone important to them, sometimes they are willing to take great risks and suffer to do certain things.
Her issues with her sister had caused their mother excessive grief, leading to her untimely death. This made Hexia feel somewhat guilty as she gradually learned the truth. Perhaps the main reason wasn't herself but her sister, yet such discomfort was not easily alleviated.