iPad registration problem

Ordinarily, you would follow this process to transfer ownership:

What to do before you sell, give away or trade in your iPhone, iPad or iPod touch – Apple Support

In your situation, this may not be necessary - read on...

The first question you need to ask relates to the purchased Apps. Were the Apps purchased using your own AppleID or your Wife’s AppleID? The answer will largely determine your way forward with Apps.

All App purchases are permanently associated with the AppleID account from which the purpose was made. Check to see who’s AppleID is currently used for App purchases. The location in Settings in which you must look differs according to the currently installed version of iOS/iPadOS.

Equipped with knowledge as to who’s AppleID “owns” the Apps will inform the strategy for Apps; more about this later.

As for transferring the iPad itself between owners, this may not necessarily require starting again. The essential step is to first disable the Activation Lock that will otherwise cause issues:

Settings > [Your Name / AppleID] > Find My > Find My iPad > Find My iPad - set to OFF

Once Find My iPad is disabled, you can sign-out of iCloud - but first, ensure that you have another device (such as an iPhone) that is is still signed-in to iCloud. If you don’t have at least one other device signed-in to iCloud, you risk complete deletion of all your personal iCloud data.

Before proceeding, ensure that you have a current iCloud or iTunes backup of the iPad.

Assuming that you are ready to sign-out from iCloud on the iPad - consider that you may have personal iCloud data linked to the iPad. During sign-out, you will have the opportunity to “save a copy” of locally stored data; if you do not wish this sensitive data (e.g., Calendar, Contacts, KeyChain etc.) to be merged with your Wife’s AppleID account, ensure that you select No:

Settings > [Your Name / AppleID] > Sign Out

Once signed-out, a restart of the iPad is recommended:

Settings > General > Shut Down

After Shut Down, restart the iPad as normal; press-and-hold the Top Button until the Apple logo appears on screen, then release the button. After restart, your Wife can sign-in to iCloud with here own AppleID - and re-enable Find My iPad.

If you have followed these instructions, the iPad will now be associated with your Wife’s AppleID account. In the unlikely event that you encounter an Activation Lock, you can resolve this from your own AppleID account. More information, if needed, can be found here:

How to remove Activation Lock – Apple Support

Now, returning to Apps - if it was previously established that Apps were purchased using your Wife’s AppleID, there’s nothing else to do. However, if Apps were actually purchased using your own AppleID, you’ll want to set-up Family Sharing.

you can continue to selectively share purchased Apple Services, Subscriptions, Apps and Media using Apple’s Family Sharing features:

Family Sharing - Apple

Set up Family Sharing – Apple Support

Share App Store, iTunes Store and Apple Books purchases with Family Sharing – Apple Support

https://www.imore.com/how-set-up-family-sharing-iphone-ipad

Hopefully this information will provide a helpful strategy to achieve your aim - and fully resolve your needs.

you can't these are the steps

What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touch - Apple Support

all data and apps are tied to the appleID so she has to start over, or you need to get a new appleID yourself and let her use the one the ipad use now.