Steve is referring to an "alleged" entry in Sheila's diary.Alleged by an author with no evidence to back it up.It does make me wonder,however,why Sheila's diary was not produced as an exhibit at trial.Instead,it was handed to the relatives as it was said to contain sensitive information that could be embarrassing for the remaining family members??
What is more interesting and relevant to the case is the fact that BW made a statement stating that Sheila had told her,prior to the murders,that "all people are evil and should be killed" !!