If the jury had been given the full history about Sheila,,then things would have turned out differently. I can assure you of that.
Adam,,Sheilas' health had deteriorated rapidly in the weeks leading up to the murders. Made worse by a GP halving vital medication which was to keep her calm. That,coupled with cannabis,,the issues over the twins was the recipe for disaster.
Sheila had it in mind that she didn't want her medication controlling her,,instead,she.herself wanted to be in control of a situation which must have been festering in her mind that night.
Even Colin said " she'd finally done it " when he was told the news that day. Did he know something that nobody else did ? Had she told him that if she wasn't going to have the twins,nobody else was ??