If you’ve already got a Google Family set up and accounts associated with it, just go into Google Calendar and you’ll see a calendar listed as “Family”. Things added to this show across all family member’s calendars, but they don’t have access to your personal calendars where you and the spouse have scheduled a trip to Chuck-E-Cheese’s without the kids.
Google Keep has added family to the collaborators. Assuming you’ve got Google Family set up create a note or drawing, then tap the three dots in the bottom right, collaborator should pop up, you can add family from there.
The people you’re adding to your family will require a Google account, and will be sent an email asking if they want to be a family member.
The most useful thing I think I’ve run across with Family is that although you don’t have to have a subscription to their music and video offerings (Google Play Music, YouTube Red,) if you do everyone has it up to a certain family size.
Should be noted that since a person has to have a Google account, it appears you’ll need to be over 12 years old to share content.
Overall it’s such an obviously needed update I have to wonder why it hasn’t been around for a long time.
Combine this with Google Location Sharing and you’ve got a lot of beautiful tools to help with managing a herd of nerf herders.