Pitcher
 

Can the pitcher step on the pitcher's plate with the ball in her glove, hands separated and then dump or flip the ball into her non glove hand before she starts her pitching motion. NFHS Fast Pitch rules.

As long as she doesn't bring her hands into contact when she transfers the ball, yes.

If the hands touch when the ball is transfered, then that's her one touch and she's committed to pitch when the hands separate.