As a 12-year old, I assumed many parental responsibilities. I took care of my younger siblings, cooked, cleaned, and managed to make good grades. The resentment I felt was tremendous. It finally came out in my being "mouthy" around the age of 16.
I imagine Calyx, especially, found herself in the same situation while her mother spent all those months in the hospital and weeks in bed. Who cooked and cleaned then?
Even worse for me is that the father felt okay leaving the country to serve with no adult truly in charge at home. With him gone, I can't begin to imagine what life was like for the children. While they may have understood that their mother was mentally ill, they certainly were nowhere near mature enough to handle the situation. Indeed, there are many adults who fall apart living with a mentally ill person. It's not easy.