There are two ways you could go about doing this:
1. Re-map your keys: Run AtomicKeys.exe to re-define what key escapes to windows
2. Set a password to exit: Run AtomicManager.exe, check-mark Advanced Options, go to the Options Tab, then Option3, check-mark "Ask for password on exiting front end" and click the Define button to set a password. For the most part, you can only use the alphabet keys; however you can also use Escape, Backspace and Space in the sequence.
Note: A keyboard is not required for this; you would simply press the buttons corresponding to your password. (Example: Right, Right, Up, Up, Down, Down)
Since kids are involved, I would recommend the password option!