Speaking about reading,while I've been looking for reference regarding June's absence from church,I've read and re-read " Freddie's "witness statement,page 4 and for the big man that he was,he was scared of Sheila's outbursts and rants,so I can imagine her behaviour on the night of the murders particularly when armed with a rifle.
This was the time when Sheila had thrown out Colin's mother from her flat.