Screen time/app time between two devices

Hello and welcome to Apple Support Communities  DeeDee616,

Thank you for contacting us. You have come to the right place and we are happy to assist you. We understand you're having an issue with your Screen Time syncing across your childs devices.  We can understand why you’d reach out for a solution. To start, make sure both devices have the most current Operating System. (Settings > General > Software Update > should be 14.7)  Check if the usage is based on daily or weekly on all devices. It may be possible that if the limits are setup for weekly, your child may have extra time for that usage still "in the week". Additionally be sure "share across devices" in checked on all devices as well.

Use Screen Time on your Mac

• "To be able to see usage information for every other device signed in to iCloud with your Apple ID, select “Share across devices” on each Mac. And on each iPhone, iPad, or iPod touch, go to Settings > Screen Time and turn on the same setting."

• "To switch between days, click within the weekly chart, or use the arrow buttons above the chart. To see total usage by week, including how much more or less time you spent compared to last week, choose This Week from the date menu at the top of the window."

After checking above steps for correct settings, if the issue still occurs, please reach back out so we can continue to assist you.

Thank you for contacting Apple Support Communities.

Best regards.