Magnifier feature is on permanently

I have a 16GB model that has a cracked screen that I will fix soon as its still been working fine but in the meantime, my daughter got to playing with it today and suddenly everything on all screens and applications is magnified! its like when you double click except its everything, including the picture of the globe! very hard to navigate on screen now to get to the slide bit at the bottom. i have no idea what she did and cos she is only 17 months old, she cant exactly explain it to me. how do i get the screen to go back to normal image size please??