Just the fact that no one seemed willing to watch them that night makes me think that Ron may have drugged them and then locked them inside so that he could go to work, meanwhile Teresa was suppose to have shown up but something kept her from showing up so she sent GMS over to check on the children. I think one of the children was unresponsive. Maybe GGMs took Jr. and went to get the nurse in the family. The nurse found that Haleigh had died. GGMS took Jr. home with her and called Teresa. Teresa came up with a plan. Someone in the Cummings family was to come by boat to the dock close to Ron's house and pick up Haleigh. I think that Ron called Tommy to get him to take the illegal drugs, guns and probably pot plants out of the home prior to the 911 call being placed. Tommy got Timmy (and maybe Joe) to come by and pick him up in the van. The pot plants were dropped off near the Mondex pond and at least one of the guns were hidden in the culvert where Ron could pick it up later. Misty finally showed up at around 2:15 am. Tommy and whichever one helped him was there and told her Haleigh was missing. Misty screamed out, neighbor heard it. Misty was seen by a neighbor around that time walking outside and crying on the cell phone. Teresa and Ron forcefully got Misty to go along with the plan. Ron left so that he could stop by the store, supposedly on his way home and Teresa left and parked near the train tracks until she was "officially" called to appear at the home.
This is a good theory and one I've often considered a possiblity. I don't think Haleigh was shot with a gun because then there would be blood and even if they tried to clean it up luminal would detect it and I'm sure that LE checked the MH out. We would no doubt would have heard about that in the media in the beginning and it more than likely wouldn't have been considered a missing child at that point if they had found a large amount of blood in the MH.