Mom & Daughter Face ID unlocks on one same single phone

If you are worried about security and do not trust technologies then please use a passcode to authenticate. Very simple.

Security safeguards

Security is important to all of us to protect information on our devices. We have done some important things to safeguard your information, the same way we did with Touch ID. Face ID uses the TrueDepth camera and machine learning for a secure authentication solution. Face ID data - including mathematical representations of your face - is encrypted and protected with a key available only to the Secure Enclave.

The probability that a random person in the population could look at your iPhone or iPad Pro and unlock it using Face ID is approximately 1 in 1,000,000 with a single enrolled appearance. As an additional protection, Face ID allows only five unsuccessful match attempts before a passcode is required. The statistical probability is different for twins and siblings that look like you and among children under the age of 13, because their distinct facial features may not have fully developed. If you're concerned about this, we recommend using a passcode to authenticate.

You live 1000's of miles away so there is no this can be checked.

Have you used Alternate Appearance?

Add an alternate appearance

For most users, Face ID will continuously learn as they change. If you have an appearance that can look vastly different, you can set up an alternate appearance so Face ID still recognizes you. You can't create a new appearance if you're wearing a face mask.

To set up an alternate appearance:

1. Go to Settings > Face ID & Passcode. If asked, enter your passcode.
2. Tap Set Up an Alternate Appearance.
3. Look straight into your iPhone or iPad and place your face inside the frame.
4. Gently move your head to complete the circle. If you're unable to move your head, tap Accessibility Options.
5. When you finish the first Face ID scan, tap Continue.
6. Gently move your head to complete the circle for a second time.
7. When Face ID setup is complete, tap Done.

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