Given the rigor mortis condition apparent on Nevill and June, I would say that the only person left alive at 06:09 was Sheila.
Why do you think Sheila killed everyone before 3.48am, then kept herself alive for another 4 hours. Shooting herself in the kitchen, before making her way upstairs (without being seen) after the police had entered WHF ?
It seems a new and just as important question from the Stokechurch investigation is who was Sheila ringing at 6.09am. Her hair dresser ?
Mike says the police shot Sheila, surely the bullets in her neck would prove this. Or was this more forgery from the police ?