if the ump doesnt call it he probly wont change his mind so its not like its really messing with the batters so my advise would just be to try and let it slide even if the ump is wrong, they dont see everything and that is the bad thing about only having one ump!!

Bring a video camera to the games, schedule a meeting to meet with the Umpire-coordinator to go over this problem, with your video proof.

It is laudable that you want the best for your daughter. But please realize that the umpire is usually a volunteer and they cannot see everything especially when they are the only one calling the game. Sometimes the best you can hope for is that they miss an similar number of calls for both teams, so both teams are treated equally. Rest assured, and reassure your daughter that the extra training will payoff when she is old enough to have umpires that do call everything. Then the other players who never learned because it was never called or didn't have extra training will be at a disadvantiage. I have personally seen this happen. Keep cheering

Wait til travel ball... they still only sometimes call, it depends what umpire...
and there are always 2 umps there and aren't always calling illegal pitches..

KUDOS to you to want to do it right! At this point, most umpires are scared to call illegal pitches. Hopefully this trend goes away, but they are reluctant to call it because most don't want the controversy. If they are professional and don't call it, simply put, they are bad umpires. If they are volunteers, it is a little more tolerable that they don't call it, but frankly they should. In the LONG RUN, (I wish umpires would see the BIG picture) it hurts the game, AND the player. How sweet is a victory if the pitcher effectively cheats to win? How sweet is the victory for the coach that knows it's illegal, but benefits from the timid umpire who won't call it?
UMPIRES: Call the illegal pitcher the first pitch of the game. Then the second. Maybe the parents will face the truth and get a pitching coach that knows what their doing, and does what's right for the player AND the SPORT that is too dominated by pitching. You'll see more offense, (which is what the sport needs, and will increase fan base) when Umpires start calling the +50% of the illegal pitchers out there. And the teams with legal pitchers (like your daughter) will start playing on an even playing field.

i'm a well seasoned umpired....even with 2 ump's working a field....it is ez to miss a illegal pitch....and depending on the quality of the game and pitching...(plz...don't let this open a can of worms)..i usually approach coach...inform them it is happening...both sides...and work from there...in say...local tourn...state or National tournament...unacceptable..bring it to the blue's attention and hope for best...if u make him split hairs...look out for both sides :)

I'm an umpire as well, (since 80s). I agree it is easy to miss an illegal pitch here and there, and sometimes hard to recognize, ESPECIALLY when doing a game alone behind the plate. But frankly, from the A position, it is not so hard to see air between the ground and the pivot foot (in a leap or crow hop), or a stutter step (which indicates the second impetus for a crow hop) (air not necessarily needed). It's the umpires most important responsibility to call the game according to ALL the rules, not decide which rules are important or not to enforce.
In baseball, when a balk occurs, umpires call it. In softball they need to as well, each and every time. In youth recreational developmental levels, both in baseball and softball, it is understandable for an umpire to confer with the coach and let them know what they are doing, AND, if both coaches agree to 'let it go' (which they shouldn't for the sake of the player) then it's excused. But in competitive levels, there is no excuse to pretend it isn't happening. And that is what I've seen too many times. And that is the umpires shortcoming, NOT the coach who is asking the umpire to call it, and any umpire who then takes it out on the coach asking, shouldn't be an umpire. Umpires need to saddle up and MAKE THE CALL!