She said lay IT in a peaceful spot. It makes no sense to lay a plastic bag in a peaceful spot so it is reasonable to assume she meant the critter, not the body bag. No harm in asking for clarification since the statement is ambiguous. It was uncharitable to assume the worst and go into full lecture mode.

I'd find a stick and just flick it out of the way or out of sight. This one is probably too old but the recently deceased can have fleas and other vermin you would rather not have a close encounter with. A plastic bag is fine as long as you don't litter if you have that much respect for our fellow creatures.

Ken