For Yao, she is free and unrestrained by nature. Of course, life is short and she should enjoy it to the fullest. Even if she changes to another world, she might as well live according to her own temperament.
Meeting Voldemort may have been a coincidence or destiny. If we decided to be together according to our temperaments, we would naturally not be entangled in them, and when it was time to leave, we would walk away calmly. However, for the powerful and domineering Voldemort, how could he let her leave what was his own.