Based on her mechanics it would be very difficult for her not to leap. Although it is open to debate if it would or would not get called. I have seen pitchers get away with worse.
All of this would be moot if the softball governing bodies would simply get a clue and let women pitch the same as men...JMHO.
Something needs to change but be careful what you wish for as that would provide an extreme advantage to the pitcher. I did this experiment with some of my very best college pitchers and the results were amazing, especially with the movement pitchers. One observer likened it to watching someone throw a wiffle ball.
Since I'm a pitching coach and not a hitting coach, I would have no problems with this change.