Set up Face ID, Touch ID, or a passcode
Set up a passcode that your child can use to unlock the device. Don’t use the same passcode on your child’s device and your own device. Remind your child not to share their passcode.
You can also set up Face ID or Touch ID so that you can unlock the device with a glance or a touch. You can enroll an Alternate Appearance for Face ID and up to five fingerprints, so add your child’s and your own.
Make sure that your child has their own Apple ID
An Apple ID is the account that you use with Messages, the App Store, and other Apple services. Everyone should have their own Apple ID, so don't share your Apple ID with your child. If your child uses your Apple ID, your child will have access to all your personal content, including text messages and photos.
If your child doesn’t have an Apple ID, you can create an Apple ID for them when you set up Family Sharing.
If your child already has an Apple ID, they should keep using it. Ask your child to sign in to appleid.apple.com and make sure that their birthday is correct.
Set up Family Sharing
With Family Sharing, you can automatically share your location with family members. And if a family member's device is missing, you can locate it on a map with the Find My app.
Families can also share subscriptions like Apple Music, iCloud storage, and more. And family members can share purchases from the App Store, iTunes Store, Apple TV app, and Apple Books.
Make sure that Find My is turned on
Set up parental controls
If you want to block or limit specific apps and features on your child’s iPhone, set up parental controls. You can restrict explicit content, prevent purchases and downloads, set limits for games, and more.
Turn on Ask to Buy
If you want kids to get permission before they buy items, download free apps, or sign up for a subscription, set up Ask to Buy. Ask to Buy is automatically on for children under 13.