The ball was misplayed and that misplay allowed her to get to first safely.
This is where I believe the rules should be clearer and say 'physical' misplay and not just misplay, which is a broad term.
I don't know if NFHS rules are different, but here are NCAA rules for softball and baseball -
NO ERROR IS CHARGED
SECTION 22. No error is charged to a fielder in the following situations:
g. When a fly ball is misjudged and the fielder cannot recover in time to make the play
IMO, in the can-o-corn example, it comes down to whether the player missed a ball because she misjudged it, or because she was there to make the play and just missed it.