My wife’s iPad is full and I want to reset it. She is worried that she will lose her photos. How can I confirm they are in iCloud?

If her iPad has iCloud Photos option enabled, go to www.icloud.com, sign in with her Apple ID & Password and click on Photos.

Before restoring her iPad to factory settings, I also suggest that you perform two important procedures:

• A full backup of your wife's iPad
• and this process too:--> Archive or make copies of the information you store in iCloud - Apple Support

Regards

Giulio