Bases Loaded Walk Ends Game (or does it?)

[BretMan]

I'm looking for an NFHS reference, but would also be interested in the ruling for others.

Bottom of the seventh, tie score, bases loaded, two outs. Batter receives ball four. All base runners advance to the next base. But the batter-runner goes about halfway to first and then...

Of course, if she goes into the dugout she's out and no run scores. But what if she stops and comes directly back toward the plate area, lining up to shake hands since the winning run has apparently scored and the game is apparently over.

Does this become an appeal situation for the defense, or is this a situation where the umpire can automatically call her out? What rule or interpretation would cover this?