They definitely had to provide for Ding Jiayi's and Qiao Donglaing's old age. Zhai Sheng might despise his mother-in-law, but he had never thought of keeping the money and shirking his responsibility of taking care of them.
If Ding Jiayi did not bring up this topic today, he might give her more money for the sake that she was being honest and she did not make any more trouble for Nan Nan.
However, Ding Jiayi brought it up today and said such harsh words. She even said that she was preparing for rainy days. It was such a joke.
Since Ding Jiayi did not give due respect to their feelings, it was up to them to decide how they wanted to provide for her in the future. It was one thing to provide for their basic needs, making sure that they were fed and clothed, and another thing to take good care of them, financially and mentally.
In the end, it was up to the children to decide how they wanted to provide for their parents.