Steve, it really matters not to me - as I am aware that Sheila definitely was the killer. Therefore I am afforded a considerable peace of mind with regard to my posting history (which has in the main been supportive of SC being the killer).
What exactly is clutching at straws here? The suggestion that Sheila was not talkative to her auntie because she was brooding over a disagreement with her parents, about a proposed reduction in her responsibility for the kids, seems a reasonable guess. It's no less clutching at straws than referring to her being zonked out by meds. After all, there had been concerns about Sheila's ability to cope and a letter was written, despite not being sent.
But it's not just that Roch. It's the pre-planning that went into this crime. The removal of the sights to prime the weapon for murder. The disappearance of the rotary dial telephone in the master bedroom and one shoved into a pile of magazines. It's the telephone call which Jeremy received from Nevill, when Nevill never consulted him before on anything.
Don't you see that no crime of this magnitude happens in a vacuum? That the person who shot and killed those people that morning harboured an all-consuming rage for many years, far likelier to have been Jeremy after being sent away for eight years, being told to start at the bottom rung of the ladder thereafter, June threatening him with disinheritance and driving Suzette away, which Jeremy may have thought caused her miscarriages, then her mother threatening to cut him out of her will? Sheila was such a dipsy character, latching onto the latest credo of the moment, whether it was June's bible, the occult or CND and the next moment she'd move onto something else, but never bitter with it. Her illness caused her to fall back into the arms of Nevill and June whether she wanted to or not, but they were kept at a distance as she struggled pitifully in laddered tights, greasy hair and body odour to attract the wealthy man which so eluded her.