I have a gut feeling that she was moved to that abandoned home from somewhere else, and it was not immediate. She could have even been in a large freezer or refrigerated device at first. we really don't know. But IIRC [ no links right now, sorry] , didn't Zach say that he was there when they removed her, and it was a body of remains, and not just bones?
I think she was 'protected' in the first week or two, then buried in a shallow grave, JMO.
ETA: Also still a possibility that she was kept alive and held somewhere for awhile.