If Sheila had wanted to kill herself initially after the first shot,,why would she have held the weapon 3 or 4 inches away from when the first wound was made ? Doesn't sound like a suicide shot to me,,as it didn't make contact with her body like the second shot did. I cannot picture a rifle going any further away in order to commit suicide. People hold weapons to their flesh,,not inches away.
I still say that it was either parent while trying to wrestle the gun from Sheila,,fired that first shot,,possibly accidentally. Being as Sheila would have been in the bedroom at the time,,it would have been June,,seeing that others were already dead. The blood drips on the bedroom carpet were Junes,,so at some point she'd just about remained mobile.
Junes' prints and those of a small person were the prints found on the bible.It doesn't mention Sheilas'.
The second shot,,yes,,that was Sheila who shot herself with a contact shot.