Trying to understand family sharing for purchased apps

I set up family sharing last week with my wife and 2 daughters.

Their id page shows they all have access to Apple tv+ but not 'purchases'.

I have enabled purchases on the family sharing page.

There doesn't seem to be an edit function on the settings page to adjust.

When they try to download an app that I have, they need to pay.

For the first time I renewed our subscription to The Week via the App store (previously directly to the magazine) and now my wife cannot read it.

So here is the question.

How can they get the apps and the subscriptions (that support family sharing) using our family sharing account?

They all have Macs, iphones and ipads running the latest software.

Thank you for any light you can light you can shed on this.