Personally I don't see her being totally incapable of doing anything, if this was the case that she could barely get out of bed I would hope June Neville and Colin would of intervened and Been of the view, if she was incapable of looking after herself, it would be potentially dangerous and totally unfair on 2 young boisterous children to be in the care of someone in this state, yes Sheila was on medication, yes it would of affected her somewhat but I don't see any responsible doctor prescribing a drug to a young mother of twins medication that rendered her incapable of doing anything, even to the point she couldn't hold a conversation.
This was the reality of her condition; she could barely get out of bed. She would save what little energy she had for the twins' weekend visits, but midweek she was a mess and needed her Maida Vale friends to let her know her hair needed washing, her make up needed applying and her body smelt. All stemmed from the Haloperidol, on which she had overdosed if anything, and the tablets she took caused tremors, making it very difficult for her to have chambered a rifle, let alone shot it with any degree of accuracy.