MNBlue wroteWithout being to wordy, it's legal as long as she doesn't do it while the pitcher is in position ready to pitch.
And when it's illegal, i.e. when the pitcher has taken a position on the pitcher's plate, the penalty is that the batter is out.
Had to check the rule book [ASA at the time] when a fellow blue made that call during the State Tournament. He had it right!