Family Sharing iCloud - Sharing All Files Saved to iCloud

My wife and I each have our own Apple account, and use family sharing through iCloud to share things like an Apple Music subscription, etc. We just upgraded our iCloud account to 200gb so that we i) have more storage, and ii) can share between the two of us. Previously, we have used Google Drive to store all of our shared files (we prefer to keep all of our files in a place where we can both access them).

How do we use iCloud (with my wife’s Apple account being the primary account) to store files where we are both able to access them? With a shared Google Drive account, either of us could just go to the app on our iPhone/iPad/PC/whatever, and view/access any of the shared files. But with iCloud, all the files are only visible if viewing from my wife’s account.

Ideas/suggestions much appreciated!