If there is a ridiculous amount of wait time to unlock, that is sometimes a glitch. Most often though it is a security reaction to too many wrong PIN attempts.
The solution is the same in any event. Hard Reset.
Power off the phone > hold Volume Down and tap Power > when you see the exclamation screen (
!) release Volume Down.
Tap in order: Volume Up / Volume Down / Power / Volume Down > you should see the spinning gears. Your device is being Factory Reset. All data will be lost, but since you are passing it along that is fine. Do not use your Microsoft Account or restore your backup. Start a new Microsoft Account for your daughter so she can start fresh. If she is young enough you will want to set up a My Family Account for her.
https://www.windowsphone.com/en-us/h...ne?signin=true
