It's time for someone on this site to upload Barbara's second statement to Police which to my recollection makes clear that her premonitions concerning ill-will to her boss were directed at Jeremy and not Sheila,as the youtube video you posted yesterday also hints at.
So far as I can gather Steve,,Nevilles' worries were nothing to do with the immediate family,it would seem. Or,,on the other hand,if it did,it would be Sheila and her" unsavoury friends",who she had befriended latterly before the tragedy. Don't forget that someone had to supply her cocaine.Better ask Julie,as she wasn't averse to a" line or two."
Neville aimed his last remark at Sheila by saying " you bring your children up to the best of your ability----------------------" In other words,,like most parents with a wayward child,they think they've failed them but it's not always the fault of the parent.