Your child's progress is saved temporarily on their tablet and is permanently saved to the Mightier servers (synced) when you have a strong wifi connection. If you log out before your data is synced that data will be lost.
You can make sure that your data is synced by following these steps below:
1.) Make sure you are connected to wifi
2.) Sync your data by following the steps below:
Click on the Gear Icon on the player selection page:
Click "Sync Data"