What was in the book that Michael didn't realize would expose the family? His aunt says how can you apologize for something you know nothing about. It couldn't be that his father was just mean. That isn't enough to cause shock.
shareShe even specifically says " Jimmy ( her now husband ) will know" It makes me think that their relationship turned physical..
There is so many unanswered questions but it seems like she had some problems also ( they talk about her having to go to the hospital ) Maybe Michael and Jane found the close relationship that they were lacking from their home lives.
I even wondered if perhaps Jane was pregnant and sent to her sister's until the resolution, ..I thought maybe she had confided in Michael and it was the reason he suggested Ryne as the new baby name. I half expected the mom's pregnancy to be fake or miscarried and her raising her sister's baby as her own.
I wish the movie hadn't been so severely editted, maybe the editted sections contained a better picture of Michael and Jane's relationship It seemed to be an interesting part of the story, and perhaps helped Michael gain some outside perspective and independence from his oppressive father.