Perhaps Lu's mother was once a bit foolish, and a bit naïve. At times when she should have fought, she did not, and when there was no need to fight, she nitpicked foolishly. Moreover, she wasn't quibbling with others, but constantly challenging herself, ultimately hurting herself and those around her.
But after her serious illness last time, she finally gained some clarity. She knew she had to be strong and couldn't continue to drift aimlessly. She also knew that it didn't matter if these people hurt her, but she would never allow them to hurt her daughter.