Illegal Pitch Question

[SF]

Game tonight - 10U softball, I'm doing plate. Fastpitch, or as fast as they get at that age. Anyway, this one pitcher is very good - fast, but also has very good control. As I was watching her motion as she was warming up I noticed that when she steps on the plate she has her shoulders slightly turned. Instead of having her shoulders even with first and third, she has them turned about 15 - 25 degrees off. Not much, in fact I couldn't really notice it behind the plate, but when I was watching her warmup I noticed. This league uses ASA rules but has them modified for the grade, so this is not supposed to be called an illegal pitch, but I wondered if you guys had seen this before and when would call an illegal pitch (assuming she's a little older and playing with full ASA rules) - is being slightly out of line enough or would you wait for it to be pronounced.