There are 2 places, on the Admin Dashboard, where you can see a postcard from home.
As a notification
In the child's profile page
Click on your name at the bottom of the sidebar menu and then Notifications.
2. Child's profile page
From the Admin Dashboard, expand Early Years and select Dashboard.
Click on the name to expand the group and select a child. Once in the child's profile page. Click the tab Postcards.