Uncover Sheila from a standing position ? I do not understand.
He just had to pull back the bed sheets (If she was not already on top of the bed). Then put one hand under her knees. The other hand under her back. And lift.
Me as a man, I do not see a problem.
But there are many problems Adam. Jeremy can't risk Sheila peeping into the twins' room or the game is up. If Sheila has to be led into the master bedroom there is June's body in the way. Sheila might also ask where Nevill is and begin to move downstairs. Mike has already stated there was none of Nevill's blood in the bedroom. Wasn't there also a droplet of June's blood found outside Sheila's bedroom?
I do believe your scenarios on the whole because Sheila was in such a state,not saying goodbye to Auntie Pam as she normally did,probably exhausted after the two weekend parties,the trip to Tiptree,the engineer whom she thought was an intruder,the monastery incident. I think Jeremy did lead her to her death,but it is not as clear cut as the guilters might wish.