One point that occurs to me is that in her first statement, Julie is very precise about when the relationship with Jeremy began: 26th. December 1983. I think she may have had a diary. The so-called diary that was produced and is viewable in the archives here is clearly not actually Julie's. Somewhere I think there was an authentic diurnal account of her relationship with Jeremy, between November 1983 and September 1985, that may have been destroyed by Julie or has been retained and secreted away somewhere.
To be fair to Julie, remember that her evidence consists only of relating what she has been told. She may well not know if Matthew Macdonald has actually been on the premises, it doesn't follow that she's lying when she says that Jeremy told her that he had.
One question that occurs to me: Do we know when Julie compiled that diary of hers? Diaries are meant to be retrospective, but Julie's diary entries read to me as if they are retroactive: in other words, she is planting information on particular dates in the past and this then forms the basis of a script for her story to the police, if you follow me.