why would she bring her own bible when there were 4 at the house?
Well I have just asked for a source that there were four bibles.
As I said bibles are personal things.
Anyway Sheila would certainly have been reading more warped religious material. She massacred her whole family. Except Bamber. It is a surprise she didn't bring this reading material with her.
She didn't just commit this crime because of the alleged supper conversation. June's bible was next to her.