All this is possible lookout but we just don't know. Julie said Jeremy told her he himself had instigated the subject of fostering and adoption that night as a way of unsettling Sheila. It's an indication to my mind that he (incredibly) still hadn't made up his mind one way or the other at that specific time whether to go ahead with the massacre.
Julie said

?
Julie said she was an honest person under oath in the witness box
Steve you must be a superhuman if you can tell when Julie Mugford was luring and when she was telling the truth
Julie had a massive motive to lie about Jeremy
You cannot keep quoting Julie said when you are trying to make a valid point??
This girl was the master of deception from the cheque book fraud to the trip to the movie to the witness box
Can you please explain why Julie stated under oath she was an honest person ?