how do I share data with family

To share data with your family members select the data you want to share and use the Share menu.

On the apple devices only the sharing of the selected items we chose to share is supported, select images in shared albums, selected folders on iCloud Drive or selected documents. But we cannot share all our data summarily. When you use family sharing for iCloud Drive, you share the storage subscription but not the documents and data. You can share the purchases and subscriptions. But the data will still be private for each family member. See: Family Sharing - Apple