I have to conclude that -
Sheila did not read the bible.
She may have read more extreme religious books.
She may have brought other religious books to WHF. Bamber either not checking, or not knowing what book page to leave another book open on.
There was one bible at WHF, not four. Which makes sense.
Sheila may not have known where the bible was.
Sheila would not have stopped to use the bible while in a spontaneous rage, after killing four people and brutally beating one person.
Sheila would not know what to look for in the bible, pre suicide.
The blood underneath the bible was Sheila's.
The blood on and inside the bible was not Sheila's as her hands were clean. She would not have attempted to read the bible after the first shot, then washed her hands.
The note inside the bible was not a suicide note.
The bible was put next to Sheila as an obvious attempt to enhance the religious aspect of the frame. By Bamber.