What is "willing suspension of belief"? How does having a willing suspension of belief help Mrs. Murry?
I think you mean the "willing suspension of disbelief". The romantic poet Colleridge came up with the phrase to explain how a reader can engage with a text even if the events or themes are not strictly realistic. The reader is encouraged to overlook the plausibility of events and just appreciate the story outside of reality. So, happily leave off what you know to be true.
As a scientist, this would allow Mrs Murray to be open to ideas that current science might not have answers for. She would be more willing to entertain the idea of a tesseract, for example.