This is substantially what I did. Differences I drew the line from where the railroad grade crosses the AT, which yielded 1.3 miles. If she took a relatively straightforward route up the railroad grade, shooting north east off of it along a beaten path to where she ended up, her walk would have been about 2 miles from the AT.
The key point raised by how far her remains were found from the trail is the question of whether the searchers should have combed over that area more thoroughly. I'm inclined to Believe that they did the best I could under the circumstances, given the resources and time pressures which prevailed.