“It’s what you learn after you know it all that counts." -- Atributed to John Wooden by Mike Candrea
IDK, just me- but big hole for a 10YO at the point where her stride foot lands is twisted ankle or worse waiting to happen. Could you have approached this as a safety issue- and pointed out the difference in the stride length of your girls vs. the other pitcher? SO that the ump could see the possible effect on your girls.
I had this happen at a 12U tournament where there were two pitching rubbers :-( My DD's stride was the right length to land right on top of it- which did not give her solid footing. they (coach) changed her out cause she had a tough time