Question About Phone Contract, On Orange??! HELP!!?

Right, I have a Blackberry C3900 Curve on an Orange contract that my mother pays for, it is a birthday present. I have gone over �15 on my account, I sent some MMS messages to my friends, do these cost money, and when the bill comes through, will my mum see the pictures I sent, please answer ASAP!!! I'm panicking!!!!!!!!!!! HELP!!!!!!!!!