I understand why people are mad for the lack of communication of the parents about Takae's ""terminal disease"", I would be too, but let me tell you guys a story about myself:
I was studying for a year when my father was hospitalized with a terminal disease, contrary to what she should do my mother didn't tell me because, according to her, "It would make my studies worse, and my father didn't want that". I was only told about the disease after my father died, and by my aunt which didn't agree with my mother's decision, which at the time was "I'll tell him his father actually died only when he come back home".
So, definetively awkward family interaction, but not irrealistic.