So, they would be using boats?
On a receding shoreline or in the water, a body makes a pretty obvious target for someone on a boat (bodies float), because they get close to shore, which is why I asked. IMO hiding a body on a lake shore is not really an effective method of concealment. If SA was an avid fisherman as you suggest, and used that lake, he no doubt would have thought of that.
Adult women typically range from 5.0 to 5.10. So she is in that range. Plus, she was a big girl. So, hiding her body would be no different from hiding the body of an adult.
As I mentioned, in earlier threads, when the body was first found, posters claimed that was an area frequented by kids to party IIRC. That is why I asked that. If they didn't party at that specific spot, where on the lake would they have?