iOS 11.3 will allow parents to approve family purchases using Face ID
iPhone X owners with children have been complaining for a while about the impossibility of approving purchases using Face ID. While on devices with Touch ID it has always been possible to approve purchases using the biometric authentication, the feature had not been implemented for Face ID …
It looks like this is going to change soon, according to our testing of the first iOS 11.3 beta. With this beta, we have been able to approve a purchase on a parent's device using Face ID. The first time a purchase approval request is received, the parent must enter their password. After entering the password for the first time, iOS asks if the parent would like to enable Face ID for future approvals.
After enabling Face ID, when a new approval request is received, tapping the "Buy" button launches Face ID authentication instead of the standard password prompt.
Source: 9to5mac