Go to account.microsoft.com/family and sign in with your Microsoft account to access Family Safety.
Once signed in, you’ll land on the ‘Your family’ page where you can view current members and click Add a family member.
Choose whether to add an existing Microsoft account (e.g., child or adult) or create a new one directly. Enter their email or phone number, then click Next.
You can now add a family member directly to your Windows device: go to:
Settings → Accounts → Family & other users, then click Add a family member
For additional information about online child safety, please see the following resources:
https://fosi.org/parenting/
https://www.commonsensemedia.org/parents-ultimate-guides