Missed plate after home run

[Fan10]

Bama/Ole Miss game on TV-Batter misses home plate after hitting an apparent homer. Plate umpire hands the catcher a new ball moments after the batter missed home. The catcher tags the batter, and the plate umpire calls the batter out.

My question is this: How long does the batter have to return home before being liable to be put out. She had not reached the dugout.

Thanks in advance