We hope you are all doing well, and are still having fun.
The Australian Childhood Foundation website has plenty of covid-19 related resources for families, including social stories to help explain covid-19, mask-wearing, and beating lockdown-boredom for children and to help them manage any worries they might have. There are activities and posters you can download too.
Their Activity Alphabet has good stay-at-home acitivity ideas too.
You can also download the story of Edna-May. It is a true story about an Australian lady, now over 100 years old, who was four years old at the time of the Spanish flu. (Story suitable for 3-6 year olds.)