My wife’s has a new iPad but forgot her 6 digit sign in code. How do I recover it

See this, If you forgot the passcode on your iPad, or your iPad is disabled - Apple Support

Click on the blue text. That is a link providing you with an Apple Support document that gives the directions to restore the device to remove the forgotten passcode. That is the only thing that you can do to remove it. Then you can restore the iPad to its latest backup.