The girls’ mother tells Helen to not worry about her father (“There’s no need to borrow trouble. I’m sure your father is fine” p. 242). Why do you suppose she was so complacent? What would you have done, if anything, had you been in her place?
I think because she knew more than she was letting on, or maybe she was also able to see or sense certain things which helped her feel secure that he was ok. I don’t think she could’ve done anything more given the circumstances.
I think her mother knew or felt that her husband was involved in something more than was evident. I think she did the right thing. I probably would have said something similar.
I think the girls’ mother knew more than she let on. This knowledge allowed her to be complacent about the whereabouts of the father. She knew he had a tendency to go off on research tangents.
She knew her husband well, and was aware of his activities, I’m sure. She most likely knew that he was being interviewed and studied rather than interrogated by the Nazis, imprisoned, or worse.
And as a practical matter, that’s the answer a parent is going to provide a child in order to protect and shield them. At least until more information becomes known and the parent has solid information to impart. We always want to avoid having our children feel consternation or pain, even if they are adults.