She loved animals, that's in one of the reports. Say the guy had a bloody rag and told her his hunting dog had been shot, could they go get it and bring it back to her house, he's right back here in the woods? If she thought time was of the essence and she planned to be right back, would she have taken the time to say anything to her brother?
I know, not that plausible, but possible.
I'm thinking that if the guy had a weapon, and he thought no one else was home, why not just force her into her car, and make her drive off? It would have bought him more time, they wouldn't have realized anything was wrong until much later in the day. Why take her straight to the woods unless he thought there was no one to see them, or he had to use coercion instead of force?