If Qiao Dongliang was willing to manage Ding Jiayi and Qiao Zijin more, Qiao Nan wouldn't have led such a painful life for the past forty years. Even if she was married to Zhai Sheng now and seemed to have a good life in the future, it wasn't because of the Qiao family's harshness to her that gave her a chance to have a life filled with happiness. She had achieved happiness by her own efforts.
As such, Qiao Nan marrying Zhai Sheng and the pain that the Qiao family brought to her were two different matters. Qiao Nan didn't feel that she should forget all her sufferings from before and treat the three people from the Qiao family as relatives just because she achieved happiness. She didn't feel that as long as Qiao Zijin wasn't too overboard, she should still help if she can since she was her sister.