https://www.google.com/maps/d/edit?mid=zZ5px4sAbxvs.kwdKIsYs1ck8
I made up a quick Google satellite map--zoom in to see the location of the accident.
Looks like maybe she did go back towards the VFW, took S Pelzer road to Mt. Gilead road. She could have easily got up to 50-60 mph along that stretch of road. She missed the stop sign at Mt. Gilead and Yankeetown and drove straight into the stipper pit. I imagine they will at least put up a highway guardrail at that location now.
Maybe she just wasn't familiar with that area and blew through the stop sign at 50 mph----no skid marks, no sign of damage. When I scale the map, the distance from the stop sign to the center of the water is about 180 feet. At 60 mph you would travel that far in a matter of seconds at full speed.
It's easy to see how it could have happened once you see the location. I'll bet the people that live in that house right next to where she was discovered are freaking out right now.