[Manny A]

Sometimes (I've seen it more in rec ball than anywhere else), a first baseman will place a tag on the BR as she returns to first base just because it's what they've been told to do. It's similar to a catcher tagging the batter after a third strike, even if the catcher caught the pitch and/or the batter cannot go to first base on an uncaught third. It's just how they've been taught, so they'll do it all the time.

That act of simply tagging the BR is nothing when the BR does make an attempt to go to second, if the defense doesn't somehow indicate to the umpire that they are appealing that the BR did make that attempt. An appeal, by definition, is a violation that the umpire doesn't make a decision until requested by the defense. Just like you wouldn't recognize a tag of a runner standing on third base after she misses second on her way from first, unless the defense makes it clear why they are tagging her, you shouldn't recognize a tag of the BR returning to first after making an attempt to go to second unless the defense accompanies that tag with some reason why they are tagging her.

How it almost always plays out is somebody is going to yell, "Tag her! She turned toward second base!" That's enough to indicate to the umpire that the defense is appealing her violation. If they say nothing and the fielder just nonchalantly tags her, you shouldn't rule her out.