"We couldn't connect to Microsoft family right now, so your family on this device might not be up to date. "

Hi, make sure you are logged in to the system using your Microsoft (Hotmail or Outlook account) not using simple Username and password.

Same here, this works!

Also, as addition: If you try to add a NEW laptop to the family account, remove your child from the family (family.microsoft.com), restart everything (computer/laptop you need to add), and then spend some frustration to add the same child again to the family. After some login here and login there, with both your account and your child account, things start to correct themselves.

Your account: Go to family account settings, and make sure the newly added child is part of your family, and allow access to the laptop/computer.

Kids account: Log in on the laptop/computer and log in at account.microsoft.com using Edge. That finally synced everything, and added the new laptop to the family overview in family.microsoft.com for the admin account. It can take a few minutes.

And... everybody is happy again.

I wanted to create admin

I have the same error message: "We couldn't connect to Microsoft Family right now..." I have this issue on two different laptops, one with Windows 10 and the other with Windows 11, which my kids use.

Unfortunately, your solution didn't work. My account is an admin account, and I am logged in with a Microsoft account.