Ma and Aba

I think it's really great that Ma has finally come our of her shell. How Nadria talks about how her mother never flinches, when she is searched by the guards, how she puts on the purple coat. How she is friends with everyone in the cafeteria. 

She is such a huge contrast compared to:

Aba. How he slumps in his chair, how he is wearing the same clothes, and how he shuffles into the courtroom. It reminded me of descriptions of grandfathers. Of elderly men, not of fathers who can hold their breath, and swim a length underwater. 

When did all of this character development happen, and why didn't I read about it?