Thank you for waiting, @WriteGirl_Office !
The thing is that our widget pulls 100 latest past events from the Google Calendar for the period of 12 last weeks. For this reason, the rest of past events aren’t displayed in the widget.
I am really sorry, but there is nothing can be done with it for now. In the meantime, I’ve added this idea to the Wishlist on your behalf - Pull all past events from Google Calendar
Let me know if you have any questions left 