With Family Sharing, you can create Apple IDs for children under 13. Apple IDs allow them to participate in Family Sharing and use other Apple services such as iCloud, iMessage, FaceTime, and Game Center.

To participate in Family Sharing, all family members must have their own Apple ID.

Children under 13 can’t create an Apple ID on their own. However, as a parent or legal guardian, the family organizer can provide verified parental consent for a child to have their own Apple ID, and then create it on the child’s behalf. If your child already has an Apple ID, you can update their email address, date of birth, security questions, and more.

When you create an Apple ID for a child, it is added to your family group automatically.

Check your payment method

Before you begin, make sure that you’re using a credit card, debit card as your payment method. You can check your payment method from your Apple ID account page or in iTunes.

To comply with child online privacy protection laws, you use the CVV, verification code sent via SMS, or security code from your payment method as part of providing your parental consent. If you have a different payment method on file, you’ll be asked to change it to a credit card, debit card, or Union Pay before you can continue.

After you create the child’s Apple ID, you can change back to a different payment method.

Create an Apple ID for your child

Use the steps below to create an Apple ID for your child, and then add them to your family group. After you add your child to your family group, they will have their own Apple ID that they can use on any Apple device.

Your email address is the rescue email address for your child’s account, and you can use it with the security questions you provided to reset a forgotten password.

If the child already has a Game Center account, but not an Apple ID, you don’t need to create a new account for them.  Just search for their nickname instead.

On an iPhone, iPad

1. Go to Settings >[your name] > Family Sharing > Add Family Member > Create a Child Account >Next. If you’re using iOS 10.2 or earlier, go to Settings > iCloud > Family.
2. Enter your child’s birthday and tap Next. Be sure to enter the correct date.
3. Review the Parent Privacy Disclosure and tap Agree.
4. Enter the requested information for your payment method and tap Next. If you don’t have a payment method on file, you need to add one.
5. Enter your child’s name, tap Next, then create their Apple ID (username@icloud.com) and tap Next. Tap Create.
6. Follow the onscreen instructions to set a password, choose security questions, and set up your child’s account. Choose passwords and security questions that you can both remember.
7. Turn on Ask to Buy to approve all iTunes, iBooks, and App Store purchases initiated by your child. You will be responsible for all charges to your account. Tap Next.
8. Review the Terms and Conditions. Tap Agree.

Manage your child’s account

Children enjoy the same Family Sharing features as other family members and, by default, can access the same music, movies, TV shows, books, and apps. You can limit what content your child can access on the devices they use. Set Restrictions or Parental Controls on an iOS device, in iTunes.

Ask to Buy is enabled by default for children under 13.* If you don’t want to use Ask to Buy, you can turn it off:

1. On your iPhone, iPad, or iPod touch, go to Settings > [your name] > Family Sharing, and tap the child’s name. If you’re using iOS 10.2 or earlier, go to Settings > iCloud > Family, and tap the child’s name.

If you turn off Ask to Buy, the child is able to initiate purchases that are billed to your payment method without prior notification.

(Source:  Apple.com)