Passcode?

If you don't know the passcode, you will need to restore your device using the computer with which you last synced it. This allows you to reset your passcode and resync the data from the device (or restore from a backup). If you restore on a different computer that was never synced with the device, you will be able to unlock the device for use and remove the passcode, but your data will not be present http://support.apple.com/kb/HT1414. These may also help:

Your granddaughter set a passcode and if she doesn't remember the passcode that she set which must be entered twice to confirm, you must restore your iPhone.

like Allan says, you have to enter it twice to set the password. It seems that if she's old enough to do that, she's old enough to remember it, no ?

i for get my passcode