In my opinion, if one had made a decision to commit suicide having prepared oneself for the act and then made the decision to pull the trigger without success a second pull of the trigger would seem to be a logical next step. In such a scenario, two pulls of the trigger are likely to occur within a few seconds of each other.
For me, the flow of blood from both wounds, given the same majority general blood flow from each of the wounds appears to support the wounds occurring within a few seconds of each other.
If this was the case, then one would expect to see two spent cases near Sheila’s body.
According to the layout diagram posted for the spent cases in the bedroom there are two spent cases near Sheila’s body. These spent cases being identified as DRH / 1 and DRH / 2.
However these spent cases are either side of Sheila’s body.
From pictures of the same type of semi automatic weapons, from the same manufacturer, it appears that spent cases are ejected away to the right hand side of the weapon.
According to the pictures of Sheila’s body, as posted on this forum, the weapon is laying on Sheila’s body with the case ejection facility laying directly against the body. If both shots have occurred within a few seconds of each other, surely it is likely both spent cases would be on the same side of her body (unless the weapon had been used either way round for each shot or Sheila had moved herself around the position of the Bible before pulling the trigger for the second fatal shot).
If the position of the body and the position of the weapon as depicted in those photographs are generally correct then the spent case for the fatal shot would surely be in the direction towards the bed.