Looking at google maps, it did look like Myra lived on a dead end dirt road beside and behind the grandmother's house. I can believe that the children traveled on the path between the two houses regularly because it clearly shows on the map. I wonder if there were aunts or uncles also living nearby? Sometimes property is divided up between the children. One big happy family.
According to the video, it sounds like the grandmother believes Myra may have come over and knocked on her door but that day they (Grandmother and whoever lived with her?) weren't home so they really wouldn't know if she did or not. The family dogs seem to lose her scent at the road. Most country family dogs are very protective of their territory and would not let a stranger get near their property but the grandmother does live on a public road. Did LE use scent dogs and they verified this?
I can see the mother telling the children to go into the house as she was leaving to do her shopping and has probably done it numerous times.
As far as the father, he was busy with the baby and if all the children had come in and were running around, I can see where he might not have noticed Myra wasn't with them until they set down to eat in one place. Is it possible they don't have a house phone and maybe a cell phone doesn't have enough bars to even work?
The guns don't bother me too much as long as they are not loaded and the ammo is locked and out of reach. I know a lot of men and women who carry a gun in their glove compartment just in case for their protection. I wonder if the father had the gun in the car and she never even thought about it? Do they have more than one car?
Since they have searched the area extensively, I guess we can rule out that Myra was snake bitten or lost in the woods.
I guess I am leaning more towards an abduction at this time.