My 2.5 year old sits on the potty 4-5x a day at school and at home every night before bath, but has yet to actually pee in the potty. She "tries" and will often push out a fart ( ) but can't seem to figure out how to release the pee. I thought by now it would have at least happened accidentally with all that time on the potty, but it hasn't and she's starting to get frustrated. How can I teach her how to let the pee out?!