I presume that it has not been accidentally moved to another page? We can have up to nine pages, I believe.
If that is not the case, it may be necessary to Restore the touch, using the button on the Summary page in iTunes when you connect the touch to the computer.
BTW, did you try to turn the touch off and then on?
Not sure how your daughter did this as this is one of the icons that does not have a X on it when we press for a second or so to enable them to be moved/deleted. I just tried (academic interest): my App Store icon shakes, but I could not delete it.