Need to add another Apple-ID on one IPad

When changing to the new ID, there may be some data loss, but you can minimize it. If syncing photos with iCloud, ensure Optimization is turned off in Settings/Your Name/iCloud/Photos and/or in Photos/Preferences/iCloud. Then make sure full resolution photos are on the device/computer. When signing out of iCloud, if asked whether you want to retain data, choose yes. Messages conversations will be lost if they are addressed to the ID. See the article below for other places that the old ID should be removed. See Winston Churchill's response in the below discussion. Also set up Family Sharing to keep access to your apps/purchases. 

 How to switch Apple IDs on your iPhone or iPad.      

How to transfer all files from one iCloud account to another.       

What to do after you change your Apple ID or password - Apple Support.      

Family Sharing.         

Family Sharing - Set up.        

Try it here. I don't usually do so on a machine my wife has two Apple IDs on. Oh, and if you meant on the mini, then no.

Try it here. I don't usually do so on a machine my wife has two Apple IDs on. Oh, and if you meant on the mini, then no.

I didn't suggest logging out. But, yes, generally speaking that is correct. Sometimes you can log out and log right back in with no problem, but I don't do it. I hope your husband gets well soon.

You are welcome.